JP7374333B2 - radar equipment - Google Patents

Description

The present application relates to a radar device.

As a conventional radar device, for example, there is a radar system described in Patent Document 1. The configuration and operation of the conventional radar device described in Patent Document 1 are as follows.

The conventional radar device described in Patent Document 1 detects objects around a vehicle that is a detection target, that is, a target object. Transmitting means constituted by at least one transmitting antenna radiate a transmitted signal towards the object. Further, a receiving means constituted by at least one receiving antenna receives a reflected signal that is a transmitted signal reflected by an object. The signal processing means processes the received signal received by the receiving means.

Received signals are obtained by different combinations of transmitting antennas and receiving antennas. For each combination, a relative phase center is determined, which is defined as the sum of the vector from the reference point to the phase center of the transmitting antenna and the vector from the reference point to the phase center of the receiving antenna.

In this case, each transmitting antenna has at least approximately the same radiation characteristics as each other. Similarly, each receiving antenna has at least approximately the same radiation characteristics as each other. However, the radiation characteristics of the transmitting antenna and the radiation characteristics of the receiving antenna may be different from each other.

At this time, it is assumed that a certain spatial direction S is perpendicular to the spatial direction R. Note that the spatial direction S is, for example, a vertical direction, and the spatial direction R is, for example, a horizontal direction. Now, regarding the position of the relative phase center, a combination of a transmitting antenna and a receiving antenna defined in the spatial direction R will be considered. In this case, the position of the relative phase center of the combination of the transmitting antenna and the receiving antenna changes periodically with a period length P.

Furthermore, the phase component of the received signal of the object alternates with a period length P depending on the angular position of the received signal with respect to the spatial direction S. Therefore, by using the phase component, the position of the object in the spatial direction S can be expressed.

Special Publication No. 2011-526373 JP 2016-3873 Publication

In the conventional radar device of Patent Document 1, the phase center spacing of receiving antennas having a plurality of element antennas is arranged at λ/2, where the average wavelength used in the radar device is λ, and power is applied to each element antenna. The feeding circuit that feeds power is a skewer-shaped feeding circuit that is not placed between each receiving antenna. In the conventional radar device of Patent Document 1, the wiring lengths of the feeding circuits to each element antenna constituting the receiving antenna are not equal, so it is not possible to achieve equal phase distribution, and the antenna frequency characteristic with a wide band, that is, the antenna frequency characteristic with a wide band, cannot be achieved. cannot be realized. For example, automotive radar uses a band of 76 to 81 GHz, but the conventional radar device of Patent Document 1 has a limit in realizing a broadband antenna with a ratio of over 2%. Other feeding methods are suitable for realizing a wideband antenna in which the ratio is 2% or more in the fractional band. Here, the fractional bandwidth is defined as A% of the frequency of the transmitted signal, and when the frequency of the transmitted signal is 77 GHz and the fractional bandwidth is 2%, the bandwidth of the antenna is approximately 1.5 GHz. Note that the bandwidth of the antenna is defined, for example, as a bandwidth such that the reflection is less than or equal to a predetermined value. As an example of the reflection being below a predetermined value, for example, the bandwidth of the antenna is defined so that the reflection is -10 dB or less. The upper limit of the fractional band is limited not only by the feeding method but also by the bandwidth of the element antennas constituting the antenna, and for example, the upper limit of the fractional band is about 10%.

As a feeder circuit that can realize equal phase distribution and wideband antenna frequency characteristics, there is a feeder circuit using a parallel feeding method (tournament method), which is formed so that the wiring lengths to each element antenna are equal. In a parallel feeding type feeding circuit, as the number of element antennas constituting one receiving antenna or transmitting antenna increases, it spreads in the horizontal direction (toward adjacent antennas), and the antennas can only be arranged at wide intervals. For example, when the frequency is 77 GHz, the wavelength λ is approximately 3.9 mm. In the conventional radar device of Patent Document 1, when a parallel feeding type feeding circuit is adopted, when the installation space of the feeding circuit becomes large, the receiving antennas are arranged with a phase center spacing wider than λ/2. Receiving antennas cannot be arranged with a phase center spacing of λ/2. For example, if receiving antennas cannot be arranged with a phase center spacing of λ/2, high side lobes or grating lobes will occur within the desired coverage area (field of view), resulting in erroneous detection of the detection target. It may be stored away. Even if the feeding circuit does not use a parallel feeding method, the detection target object may be erroneously detected even when power is fed to each element antenna from the lateral direction (direction of adjacent antennas). The desired viewing range is a viewing range set by design, that is, a designed viewing range.

Assuming that the distance that is the phase center spacing of the receiving antenna is d, this distance d is determined according to the setting of the viewing range, that is, the range of angles θ that can be measured. For example, when the angle θ is −90° or more and 90° or less, the distance d needs to be in the range of greater than 0 and less than or equal to λ/2. In the conventional radar device of Patent Document 1, when a power feeding circuit that feeds power from the horizontal direction such as a parallel feeding method is adopted, the radar device of Patent Document 1 is configured to maintain an angle θ of -90° or more and 90° or less at a predetermined distance d. It is not possible to arrange three or more receiving antennas at intervals.

The technology disclosed in this specification is a radar device that can reduce side lobes and suppress false detection even when receiving antennas or transmitting antennas of three or more channels cannot be physically arranged at predetermined distance intervals. The purpose is to provide

An example radar device disclosed in this specification includes a plurality of transmitting antennas that radiate a transmitted signal toward a target object, and receives a reflected signal obtained by reflecting the transmitted signal from the target object and outputs it as a received signal. It includes a plurality of receiving antennas and a processing section that processes the received signals output from each of the plurality of receiving antennas. An antenna group with either multiple transmitting antennas or multiple receiving antennas, with the antenna spacing between adjacent antennas determined based on the field of view required for the radar device as the basic distance, and adjacent antennas. An antenna group including a first antenna set having a plurality of first antennas in which the antenna spacing between the antennas is a basic distance is defined as a first antenna group, and the antenna group includes a plurality of antennas different from the first antenna of the first antenna group. A second antenna group is an antenna group including a second antenna group having a plurality of second antennas in which the antenna spacing between adjacent antennas is twice the basic distance. The first antenna and the second antenna each include a plurality of element antennas and a power feeding circuit that feeds power to the element antennas. The plurality of first antennas are arranged side by side in a first arrangement direction perpendicular to the transmission direction of the transmission signal, and have respective feeding circuits on the positive side or the negative side of the first arrangement direction. The plurality of second antennas are arranged in a second arrangement direction perpendicular to the transmission direction of the transmission signal and parallel to the first arrangement direction, and have a feeding circuit on the positive side or the negative side of the second arrangement direction. There is. No feeding circuit is arranged between adjacent antennas in the first antenna set. A virtual reception antenna group is configured of a plurality of virtual reception antennas formed by a plurality of first antennas of the first antenna group and a plurality of second antennas of the second antenna group. They are arranged side by side in a third arrangement direction parallel to the arrangement direction and the second arrangement direction, and the interval between adjacent virtual receiving antennas in the third arrangement direction is the basic distance.

An example radar device disclosed in the present specification includes a first antenna group having a plurality of first antennas in which the antenna interval between adjacent antennas is a basic distance, and a second antenna group is adjacent to each other. a second antenna set having a plurality of second antennas in which the antenna spacing between the antennas is twice the basic distance, and a plurality of virtual reception antennas formed by transmission and reception of the plurality of first antennas and the plurality of second antennas; Since the distance between adjacent virtual receiving antennas is the basic distance, even if receiving antennas or transmitting antennas of three or more channels cannot be physically arranged at a predetermined distance, side lobes can be reduced and false detections can be avoided. can be suppressed.

1 is a diagram showing the configuration of a radar device according to Embodiment 1. FIG. FIG. 2 is a diagram illustrating an example of a hardware configuration that implements the functions of a processing section in FIG. 1. FIG. 2 is a diagram showing a first example of antenna arrangement of the radar device according to Embodiment 1. FIG. FIG. 4 is a diagram showing details of the antenna arrangement of FIG. 3; FIG. 3 is a diagram illustrating an angle measurement method of the radar device according to the first embodiment. FIG. 3 is a diagram showing an example of a modulation pattern of the radar device according to the first embodiment. 4 is a diagram showing a virtual reception antenna group corresponding to the antenna arrangement of FIG. 3. FIG. 5 is a flowchart showing processing of the radar device according to the first embodiment. FIG. 3 is a diagram showing a second example of antenna arrangement of the radar device according to the first embodiment. 10 is a diagram showing details of the antenna arrangement in FIG. 9; FIG. 10 is a diagram showing a virtual reception antenna group corresponding to the antenna arrangement of FIG. 9. FIG. FIG. 3 is a diagram showing a third example of antenna arrangement of the radar device according to Embodiment 1; 13 is a diagram showing a first example of a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 12. FIG. 13 is a diagram showing a second example of a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 12. FIG. 1 is a diagram showing a first example of an antenna of a radar device according to Embodiment 1. FIG. FIG. 3 is a diagram showing a second example of the antenna of the radar device according to the first embodiment. FIG. 7 is a diagram showing a third example of the antenna of the radar device according to the first embodiment. FIG. 7 is a diagram showing a fourth example of the antenna of the radar device according to the first embodiment. FIG. 7 is a diagram showing a fifth example of the antenna of the radar device according to the first embodiment. FIG. 7 is a diagram showing a sixth example of the antenna of the radar device according to the first embodiment. FIG. 7 is a diagram showing a fourth example of antenna arrangement of the radar device according to Embodiment 1; 22 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 21. FIG. FIG. 7 is a diagram showing a fifth example of antenna arrangement of the radar device according to Embodiment 1; FIG. 7 is a diagram showing a sixth example of antenna arrangement of the radar device according to Embodiment 1; FIG. 7 is a diagram showing a seventh example of antenna arrangement of the radar device according to Embodiment 1; 26 is a diagram showing a virtual reception antenna group corresponding to the antenna arrangement of FIG. 25. FIG. FIG. 7 is a diagram showing an antenna arrangement of a radar device according to a second embodiment. 28 is a diagram showing a virtual reception antenna group corresponding to the antenna arrangement of FIG. 27. FIG. FIG. 7 is a diagram showing an antenna arrangement of a radar device according to a third embodiment. 30 is a diagram showing the arrangement of transmitting antennas in FIG. 29; FIG. 30 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 29. FIG. FIG. 7 is a diagram showing an antenna arrangement of a radar device according to a fourth embodiment. FIG. 33 is a diagram showing the arrangement of transmitting antennas in FIG. 32; 33 is a diagram showing a virtual reception antenna group corresponding to the antenna arrangement of FIG. 32. FIG. FIG. 35 is a diagram showing the first virtual receiving antenna group of FIG. 34; 35 is a diagram showing a second virtual receiving antenna group in FIG. 34. FIG. FIG. 7 is a diagram showing an antenna arrangement of a radar device according to a fifth embodiment. 38 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 37. FIG. FIG. 38 is a diagram showing a third virtual receiving antenna group in FIG. 37; FIG. 7 is a diagram showing an antenna arrangement of a radar device according to a sixth embodiment. 41 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 40; FIG. FIG. 42 is a diagram showing the first virtual reception antenna group of FIG. 41; 42 is a diagram showing a second virtual receiving antenna group in FIG. 41. FIG. 42 is a diagram showing a third virtual receiving antenna group in FIG. 41. FIG.

Embodiment 1.
FIG. 1 is a diagram showing the configuration of a radar device according to the first embodiment, and FIG. 2 is a diagram showing an example of the hardware configuration that implements the functions of the processing section in FIG. 1. FIG. 3 is a diagram showing a first example of antenna arrangement of the radar device according to the first embodiment, and FIG. 4 is a diagram showing details of the antenna arrangement of FIG. 3. FIG. 5 is a diagram illustrating an angle measurement method of the radar device according to the first embodiment, and FIG. 6 is a diagram illustrating an example of a modulation pattern of the radar device according to the first embodiment. FIG. 7 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 3, and FIG. 8 is a flowchart showing processing of the radar device according to the first embodiment. FIG. 9 is a diagram showing a second example of antenna arrangement of the radar device according to the first embodiment. 10 is a diagram showing details of the antenna arrangement in FIG. 9, and FIG. 11 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement in FIG. 9. FIG. 12 is a diagram showing a third example of antenna arrangement of the radar device according to the first embodiment. FIG. 13 is a diagram showing a first example of a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 12, and FIG. 14 is a diagram showing a second example of a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 12. FIG. 15 is a diagram showing a first example of the antenna of the radar device according to the first embodiment, and FIG. 16 is a diagram showing a second example of the antenna of the radar device according to the first embodiment. FIG. 17 is a diagram showing a third example of the antenna of the radar device according to the first embodiment, and FIG. 18 is a diagram showing a fourth example of the antenna of the radar device according to the first embodiment. FIG. 19 is a diagram showing a fifth example of the antenna of the radar device according to the first embodiment, and FIG. 20 is a diagram showing a sixth example of the antenna of the radar device according to the first embodiment. FIG. 21 is a diagram showing a fourth example of the antenna arrangement of the radar device according to the first embodiment, and FIG. 22 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 21. FIG. 23 is a diagram showing a fifth example of antenna arrangement of the radar device according to Embodiment 1, and FIG. 24 is a diagram showing a sixth example of antenna arrangement of the radar device according to Embodiment 1. FIG. 25 is a diagram showing a seventh example of antenna arrangement of the radar device according to Embodiment 1, and FIG. 26 is a diagram showing a virtual reception antenna group corresponding to the antenna arrangement of FIG. 25. In each figure, the same or corresponding components are indicated by the same reference numerals, and redundant explanations will be omitted.

The radar device 1 according to the first embodiment includes a processing section 11, a transmitting circuit 12, a receiving circuit 13, a plurality of transmitting antennas Tx1 and Tx2, and a plurality of receiving antennas Rx1, Rx2, Rx3, and Rx4. A structural unit such as Tx1, Tx2, Rx1, Rx2, Rx3, and Rx4 that is processed as one antenna is called a channel. Hereinafter, when the transmitting antennas Tx1 and Tx2 are referred to collectively, they are referred to as transmitting antennas Tx, and similarly, when referring to receiving antennas Rx1, Rx2, Rx3, and Rx4 collectively, they are referred to as receiving antennas Rx.

The radar device 1 is mounted on a moving body. When the moving object is a vehicle, the radar device 1 is connected to an ECU (Electronic Control Unit) 2 of the vehicle.

Note that in the radar device 1 shown in FIG. 1, an example is given in which the number of transmitting antennas Tx is two and the number of receiving antennas Rx is four. However, in the radar device 1 of the first embodiment, as in the third example of the antenna arrangement of the radar device 1 shown in FIG. The configuration may be any configuration as long as it includes first antennas At1a and At1b, which are two transmitting antennas or receiving antennas, arranged as shown in FIG. When the first antenna is the transmitting antenna Tx, the second antenna is the receiving antenna Rx, and when the first antenna is the receiving antenna Rx, the second antenna is the transmitting antenna Tx. FIG. 12 shows an example including four second antennas At2a, At2b, At2c, and At2d. When the first antennas At1a and At1b are collectively called the first antenna At1, similarly, when the second antennas At2a, At2b, At2c, and At2d are collectively called the second antenna At2.

The radar device 1 radiates a transmission signal generated by the transmission circuit 12 toward the target object 33 from the transmission antenna Tx1 or the transmission antenna Tx2 (see FIG. 5). The transmitted signal is reflected by the target object 33 that is the detection target. A reflected signal, which is a reflected signal, is received by a receiving antenna Rx. The received signal is input to the processing unit 11 via the receiving circuit 13 as a received signal. The processing unit 11 performs signal processing on the received signal to determine the distance to the target object 33, the relative speed of the target object 33, and the angle at which the target object 33 exists (hereinafter, the distance, relative speed, and angle of the target object). , angle). The configuration of each part of the radar device 1 will be explained below.

The processing unit 11 controls the operation of each unit, such as the transmitting antenna Tx, the receiving antenna Rx, the transmitting circuit 12, and the receiving circuit 13, which constitute the radar device 1. Further, the processing unit 11 generates a transmission signal transmitted from the transmission antenna Tx, and performs signal processing on the reception signal received by the reception antenna Rx, thereby calculating the distance, relative velocity, and angle of the target object. .

The processing unit 11 includes a processor 98 composed of, for example, a one-chip microcomputer having a CPU (Central Processing Unit) function or a PLD (Programmable Logic Device) such as an FPGA (Field-Programmable Gate Array); AM (Random Access The memory 99 includes a ROM (Read Only Memory) and a ROM (Read Only Memory). The functions of the processing unit 11 are realized by the processor 98 executing a program stored in the memory 99. Furthermore, multiple processors 98 and multiple memories 99 may cooperate to execute each function. Details of the operation of the processing unit 11 will be described later.

The transmission circuit 12 includes a voltage generation circuit 121, a voltage controlled oscillator 122, a distribution circuit 123, and a transmission changeover switch 124. The voltage generation circuit 121 generates a desired voltage waveform at a timing controlled by the processing unit 11. The voltage controlled oscillator 122 generates and oscillates a transmission signal based on the voltage waveform generated by the voltage generation circuit 121. FIG. 6 shows an example of a modulation pattern 61 of a transmission signal. The desired voltage waveform is a voltage waveform set by design, that is, a designed voltage waveform.

The distribution circuit 123 appropriately amplifies the transmission signal oscillated from the voltage controlled oscillator 122. The distribution circuit 123 outputs the amplified transmission signal to the transmission changeover switch 124 and also to mixers 131, 132, 133, and 134 provided in the reception circuit 13, which will be described later.

The transmission changeover switch 124 is connected to the transmission antenna Tx1 and the transmission antenna Tx2, and switches the output destination between the transmission antenna Tx1 and the transmission antenna Tx2 under the control of the processing unit 11. Therefore, the transmission signal output from the distribution circuit 123 is radiated as a beam of electromagnetic waves from the transmission antenna Tx1 or Tx2 depending on the state of the transmission changeover switch 124.

The emitted electromagnetic waves are reflected by the target object 33. The electromagnetic waves reflected by the target object 33 are received by receiving antennas Rx1, Rx2, Rx3, and Rx4, respectively. Reception signals received by reception antennas Rx1, Rx2, Rx3, and Rx4 are input to reception circuit 13.

The receiving circuit 13 includes mixers 131, 132, 133, 134, filter circuits 141, 142, 143, 144, and analog/digital converters 151, 152, 153, 154. The analog-to-digital converter is suitably an ADC (Analog-to-Digital Converter).

Mixers 131, 132, 133, 134, filter circuits 141, 142, 143, 144, and ADCs 151, 152, 153, 154 are provided for each receiving antenna Rx1, Rx2, Rx3, Rx4, respectively. It is being

The mixers 131, 132, 133, and 134 receive the received signals received by the respective receiving antennas Rx1, Rx2, Rx3, and Rx4. Further, as described above, the transmission signal is inputted to the mixers 131, 132, 133, and 134 from the distribution circuit 123 of the transmission circuit 12. Each mixer 131, 132, 133, 134 mixes the reception signal received by each reception antenna Rx1, Rx2, Rx3, Rx4 with the transmission signal input from the distribution circuit 123 of the transmission circuit 12, and outputs the mixed signal. do.

The filter circuits 141, 142, 143, and 144 include a bandpass filter that extracts a signal in a desired frequency band and an amplifier circuit that amplifies the signal. Filter circuits 141, 142, 143, and 144 extract and amplify only signals in desired frequency bands from the mixed waves output from mixers 131, 132, 133, and 134, respectively, and output the signals as received signal voltages. . The desired frequency band is a frequency band set by design, that is, a designed frequency band.

The ADCs 151, 152, 153, and 154 include converters that perform A/D conversion to convert analog signals into digital signals. The ADCs 151, 152, 153, and 154 A/D convert the received signal voltages output from the filter circuits 141, 142, 143, and 144 to digital voltage data at timings controlled by the processing unit 11. The digital voltage data is input to the processing section 11, stored in the memory 99 of the processing section 11, and used in arithmetic processing described later.

Next, the transmitting antenna Tx and receiving antenna Rx will be explained. The transmitting antennas Tx1, Tx2 and the receiving antennas Rx1, Rx2, Rx3, Rx4 each include a plurality of element antennas 19 and a feeding circuit 25, and are arranged in a plane as shown in FIGS. 3 and 4. has been done. The element antenna 19 is, for example, a patch antenna.

The transmitting antenna Tx and the receiving antenna Rx are arranged on the surface of the substrate 23. The transmitting antenna Tx and the receiving antenna Rx may be placed on the same board 23 as shown in FIG. 4, or the transmitting antenna Tx may be placed on one board and the receiving antenna Rx on another board as shown in FIG. They may be arranged on one substrate. FIG. 24 shows an example in which the transmitting antenna Tx is arranged on the substrate 23a and the receiving antenna Rx is arranged on the substrate 23b.

In the radar device 1 of the first embodiment, each transmitting antenna Tx and each receiving antenna Rx are each formed by a combination of a plurality of element antennas 19. For example, in the first example of the antenna arrangement shown in FIGS. 3 and 4, if a white square is one element antenna 19, each transmitting antenna Tx is composed of four element antennas 19. Further, each receiving antenna Rx is composed of four element antennas 19. Note that the number of element antennas 19 is not limited to four, and may be set to any number as appropriate.

The transmitting antenna Tx1 and the transmitting antenna Tx2 are designed to have substantially the same radiation characteristics. Similarly, receiving antennas Rx1, Rx2, Rx3, and Rx4 are designed to have substantially the same radiation characteristics. Substantially the same radiation characteristics are radiation characteristics within an allowable difference. However, the radiation characteristics of the transmitting antenna Tx and the radiation characteristics of the receiving antenna Rx may be different from each other. Note that the radiation direction of the radio waves radiated from the transmitting antenna Tx is a direction perpendicular to the plane of the substrate 23, that is, the front or back surface. In FIG. 4, this is a direction perpendicular to the paper surface.

The transmitting antenna Tx1 includes a plurality of element antennas 19 arranged along a phase center line 28a passing through the phase center Ct1. The transmitting antenna Tx2 includes a plurality of element antennas 19 arranged along a phase center line 28b passing through the phase center Ct2. A plurality of element antennas 19 of the transmitting antenna Tx are arranged along a phase center line passing through the phase center. Similarly to the transmitting antenna Tx, the receiving antennas Rx1, Rx2, Rx3, and Rx4 are also arranged along a phase center line in which the plurality of element antennas 19 of each antenna passes through the phase center. The receiving antenna Rx1 includes a plurality of element antennas 19 arranged along the phase center line 27a passing through the phase center Cr1, and the receiving antenna Rx2 is arranged along the phase center line 27b passing through the phase center Cr2. A plurality of element antennas 19 are provided. The receiving antenna Rx3 includes a plurality of element antennas 19 arranged along the phase center line 27c passing through the phase center Cr3, and the receiving antenna Rx4 is arranged along the phase center line 27d passing through the phase center Cr4. A plurality of element antennas 19 are provided. The direction in which the phase center line of each of the transmitting antenna Tx and the receiving antenna Rx extends is also the direction in which the plurality of element antennas 19 extend.

As shown in FIGS. 3 and 4, the transmitting antennas Tx are arranged in parallel on the surface of the substrate 23 so that they are parallel to each other, that is, so that their phase center lines are parallel. Hereinafter, the arrangement direction of the transmitting antennas Tx will be referred to as a first arrangement direction dr1. The first arrangement direction dr1 is a direction perpendicular to the transmission direction of the transmission signal, and is a direction perpendicular to the phase center lines 28a, 28b. Further, if a certain distance, which will be described later and is determined according to the desired field of view range of the radar device 1, is a distance d, then the transmitting antenna interval Dtx between the two transmitting antennas Tx1 and Tx2, that is, the phase center line 28a The interval between the phase center line 28b and the phase center line 28b is equal to the distance d. The desired viewing range is a viewing range set by design to satisfy the required viewing range, that is, a designed viewing range.

Further, as shown in FIGS. 3 and 4, the receiving antennas Rx are arranged on the surface of the substrate 23 so that they are parallel to each other, that is, so that their phase center lines are parallel to each other. Hereinafter, the arrangement direction of the receiving antennas Rx will be referred to as a second arrangement direction dr2. The second arrangement direction dr2 is a direction perpendicular to the transmission direction of the transmission signal, and is a direction perpendicular to the phase center lines 27a to 27d . The first arrangement direction dr1 and the second arrangement direction dr2 are parallel to each other. 3 and 4 show an example in which the phase centers Ct1, Ct2 of the transmitting antenna Tx and the phase centers Cr1, Cr2, Cr3, Cr4 of the receiving antenna Rx are arranged on the same axis. The transmitting antennas Tx1 and Tx2 are arranged in order toward the positive side in the first arrangement direction dr1, and the receiving antennas Rx1, Rx2, Rx3, and Rx4 are arranged in order toward the positive side in the second arrangement direction dr2. In FIGS. 3 and 4, the spacing Drx between adjacent receiving antennas Rx1, Rx2, Rx3, and Rx4 is twice the distance d, that is, 2d.

The transmitting antennas Tx1 and Tx2 include a power feeding circuit 25 that feeds power to each element antenna 19. Similarly, receiving antennas Rx1, Rx2, Rx3, and Rx4 include a power feeding circuit 25 that feeds power to each element antenna 19. 3 and 4, as an example of the feed circuit 25, a parallel feed circuit in which the wiring lengths to each element antenna 19 are equal is shown. For the transmitting antennas Tx1 and Tx2, the feeding circuit 25 is arranged on the positive side or the negative side in the first arrangement direction dr1, and for the receiving antennas Rx1, Rx2, Rx3, and Rx4, the feeding circuit 25 is arranged on the positive side or the negative side in the second arrangement direction dr2. It is placed on the negative side. The transmitting antennas Tx1 and Tx2 are arranged so that the element antennas 19 face each other so that the feeding circuit 25 is not arranged in a region adjacent to other transmitting antennas. The receiving antennas Rx1, Rx2, Rx3, and Rx4 are arranged such that the feeding circuit 25 is arranged in a region adjacent to other receiving antennas, and the element antennas 19 do not face each other. Here, an antenna group that includes a pair of antennas whose antenna spacing is less than or equal to distance d is defined as a first antenna group Gr1, and an antenna group that does not include a pair of antennas whose antenna spacing is less than or equal to distance d is defined as a second antenna group. Let it be group Gr2. In the first example of the antenna arrangement shown in FIGS. 3 and 4, the transmitting antennas Tx1 and Tx2 are the antennas of the first antenna group Gr1, and the receiving antennas Rx1, Rx2, Rx3, and Rx4 are the antennas of the second antenna group Gr2. be.

In the radar device 1 of the first embodiment, the transmitting antenna Tx and the receiving antenna Rx form a virtual receiving antenna. The virtual reception antenna refers to a virtual reception antenna formed by multiple input multiple output (MIMO) technology. Generally, it is often composed of a plurality of transmitting antennas arranged at a first interval and a plurality of receiving antennas arranged at a second interval narrower than the first interval. The receiving antenna is configured to interpolate between the widely spaced transmitting antennas by receiving the signal using the receiving antenna and subjecting it to signal processing. A virtual receiving antenna group is configured by a plurality of virtual receiving antennas. In radar equipment that forms multiple virtual receiving antennas, the number of virtual receiving antennas is the number of receiving antennas x the number of transmitting antennas, and the desired number of receiving antennas can be achieved with a smaller number of receiving antennas than when there is only one transmitting antenna. Antenna directivity can be achieved. The desired antenna directivity is the antenna directivity set by design, that is, the designed antenna directivity.

FIG. 7 shows a virtual reception antenna group 50 formed by the transmission antenna Tx and reception antenna Rx in the first example of the antenna arrangement shown in FIGS. 3 and 4. The virtual reception antenna group 50 includes a plurality of virtual reception antennas, and is composed of a plurality of virtual reception antennas. Two transmitting antennas Tx1, Tx2 and four receiving antennas Rx1, Rx2, Rx3, Rx4 form eight virtual receiving antennas VR1, VR2, VR3, VR4, VR5, VR6, VR7, VR8. The radar device 1 according to the first embodiment is configured such that adjacent antennas in the virtual receiving antennas VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8 are equally spaced at a distance d. Note that each virtual receiving antenna is displayed as a circle. The center of the circle corresponds to the phase center of the transmitting antenna Tx and the receiving antenna Rx. When the virtual reception antennas VR1 to VR8 are collectively referred to as a virtual reception antenna VR, the arrangement direction of the virtual reception antenna VR is called a third arrangement direction dr3. The virtual receiving antennas of the virtual receiving antenna group 50 are arranged at equal distances d in the third arrangement direction dr3. In the first example of the antenna arrangement shown in FIGS. 3 and 4, the phase centers of the transmitting antenna Tx and the receiving antenna Rx are arranged on the same axis, so each virtual receiving antenna VR of the virtual receiving antenna group 50 is arranged on the same axis. It is located. The third arrangement direction dr3 is a direction perpendicular to the transmission direction of the transmission signal and parallel to the first arrangement direction dr1 and the second arrangement direction dr2.

In the example of FIG. 7, virtual receiving antennas VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8 are arranged toward the positive side of the third arrangement direction dr3, respectively. , VR4, and VR8. Among these virtual receiving antenna groups 50, VR1, VR2, VR3, and VR4 indicated by solid circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx1 and received by the receiving antennas Rx1, Rx2, Rx3, and Rx4. VR5, VR6, VR7, and VR8 indicated by broken line circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx2 and received by the receiving antennas Rx1, Rx2, Rx3, and Rx4.

Next, we will discuss how to determine the distance d, as well as the transmitting antenna spacing Dtx, which is the spacing between adjacent transmitting antennas in the transmitting antenna Tx, the receiving antenna spacing Drx, which is the spacing between adjacent receiving antennas in the receiving antenna Rx, and the virtual A method for determining the virtual receiving antenna spacing Dvr, which is the spacing between adjacent virtual receiving antennas VR in the receiving antenna group 50, will be described.

As described above, in the first example of the antenna arrangement shown in FIGS. 3 and 4, the transmitting antennas Tx1 and Tx2 are arranged in the first array direction dr1 with the transmitting antenna spacing Dtx being the distance d, and each The receiving antennas Rx1, Rx2, Rx3, and Rx4 are arranged in the second arrangement direction dr2 at a spacing Drx between adjacent receiving antennas, which is twice the distance d, that is, 2d.

In the radar apparatus 1 of the first embodiment, under the control of the processing unit 11, transmission signals are alternately radiated from the transmission antenna Tx1 and the transmission antenna Tx2, for example, according to a modulation pattern 61 shown in FIG. 6, which will be described later. At this time, the radar device 1 uses four channels of signals transmitted from the transmitting antenna Tx1 and received by the receiving antennas Rx1, Rx2, Rx3, and Rx4, and signals transmitted from the transmitting antenna Tx2 and received by the receiving antennas Rx1, Rx2, Rx3, and Rx4. It is possible to receive signals of a total of 8 virtual reception channels, including 4 channels of received signals. As shown in FIG. 7, the virtual reception channels are a total of eight channels that are received by virtual reception antennas VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8, respectively. The virtual reception channels of the virtual reception antennas VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8 are virtual reception channels VRC1, VRC2, VRC3, VRC4, VRC5, VRC6, VRC7, and VRC8.

As described above, in the radar device 1 of the first embodiment, the virtual receiving antenna interval Dvr of the virtual receiving antennas VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8 is set to the distance d. The distance d is a value determined so as not to generate a grating lobe in the field of view of the radar device 1. In general, if the wavelength of the radio wave is λ, if a plurality of virtual receiving antennas VR are arranged at λ/2 intervals in the third arrangement direction dr3, the beam will be emitted in the direction perpendicular to the third arrangement direction dr3, that is, in the radiation direction. It is possible to design an antenna (virtual reception antenna group 50) that does not generate grating lobes even if the antenna is swung within a range of ±90°. The viewing range of the radar device 1 can also be considered as a viewing range that allows angle measurement without ambiguity, that is, a viewing range that allows highly accurate angle measurement. That is, by setting the distance d to λ/2, it is possible to realize a radar device having a viewing range of ±90° and capable of highly accurate angle measurement without generating grating lobes.

For example, consider a phase monopulse type radar device. In this case, as shown in FIG. 5, for example, the virtual receiving antenna interval Dvr between two virtual receiving antennas VR1 and VR5 is d, the wavelength of the transmission signal is λ, and the two virtual receiving antennas VR1 and VR5 are When the phase difference with VR5 is φ, the following relationship holds true between the phase difference φ and the angle θ of the target object 33. Here, the angle θ is the angle of the target object 33 when the radiation direction of the transmission signal is θ=0, as shown in FIG.

φ=(2πd/λ)・sinθ...(1)
θ=sin-1(φλ/2πd)...(2)

Now, the phase difference φ is in the range of ±π. Therefore, when the distance d is large, the viewing range of the radar device 1, that is, the range of angles θ that can be measured becomes narrow. On the other hand, when the distance d is small, the viewing range of the radar device 1, that is, the range of angles θ that can be measured becomes wide. As is clear from equations (1) and (2), for example, in order to measure the angle θ within the viewing range of -90°≦θ≦+90°, the distance d must be set in the range d≦λ/2. You need to set it so that

In this way, the distance d is a value determined according to the desired viewing range required of the radar device 1, that is, the range of the angle θ desired to be measured. In other words, if the virtual receiving antenna spacing Dvr between adjacent virtual receiving antennas VR is larger than the distance d, a desired wide viewing range of the radar device 1 cannot be secured. Therefore, if it is desired to realize angle measurement processing in a desired wide field of view of the radar device 1, it is necessary to set the virtual receiving antenna spacing Dvr between adjacent virtual receiving antennas VR to be less than or equal to the distance d. There is. When setting the virtual receiving antenna spacing Dvr between adjacent virtual receiving antennas VR to be equally spaced at a distance d, the arrangement of the feeding circuit 25 of the transmitting antenna Tx and the receiving antenna Rx, since the required value is the maximum, The degree of freedom regarding the size of the element antenna 19, etc. can be increased.

Further, the distance d also changes depending on the wavelength λ of the transmission signal from the relationship in equation (2). Therefore, when the wavelength λ of the transmission signal is variable, the distance d is determined based on the desired viewing range of the radar device 1 and the wavelength λ of the transmission signal.

Next, the operation of the radar device 1 will be explained. First, in the transmitting circuit 12, the voltage generating circuit 121 generates a desired voltage waveform at a timing controlled by the processing section 11. The voltage controlled oscillator 122 generates and outputs a transmission signal based on the generated voltage waveform. The distribution circuit 123 outputs the transmission signal to the transmission changeover switch 124 and also to the mixers 131, 132, 133, and 134 of the reception circuit 13. The transmission signal is radiated from the transmission antenna Tx1 or Tx2 depending on the state of the transmission changeover switch 124.

The emitted transmission signal is reflected by the target object 33. A reflected signal, which is a transmitted signal reflected from the target object 33, is received by each receiving antenna Rx1, Rx2, Rx3, and Rx4, and is input to the receiving circuit 13 as a received signal.

In the receiving circuit 13, for each receiving antenna Rx1, Rx2, Rx3, Rx4, mixers 131, 132, 133, 134, filter circuits 141, 142, 143, 144, and ADCs 151, 152, 153, 154, Each is connected.

In the reception circuit 13, each mixer 131, 132, 133, 134 mixes the transmission signal from the distribution circuit 123 and the reception signal from the reception antennas Rx1, Rx2, Rx3, Rx4. Next, filter circuits 141, 142, 143, and 144 extract only signals in a desired frequency band from the mixed signals. The ADCs 151, 152, 153, and 154 A/D convert the received signal voltages that are the outputs of the filter circuits 141, 142, 143, and 144 at timings controlled by the processing unit 11 to obtain digital voltage data. The digital voltage data is input to the processing section 11 and stored in the memory 99. The processing unit 11 reads the digital voltage data from the memory 99 and uses it in calculation processing described later.

Next, details of the operation of the processing section 11 will be explained. A case will be described in which the radar device 1 of the first embodiment is, for example, a radar device (time-division MIMO) that uses the FCM (Fast Chirp Modulation) method and transmits by temporally switching the transmitting antennas Tx1 and Tx2. Note that the radar device 1 of the first embodiment is not limited to the FCM radar system, but can be applied to various radar systems such as the FM-CW (Frequency Modulated Continuous Wave) system and the pulse Doppler system. It is.

FIG. 6 shows an example of a modulation pattern when transmission is performed by temporally switching the transmitting antennas Tx1 and Tx2 using the FCM method. As shown in FIG. 6, in the FCM method, electromagnetic waves whose frequency is modulated to rise (up) or fall (down) at a constant slope are repeatedly transmitted. The horizontal axis is time, and the vertical axis is the voltage of the transmitted signal. Hereinafter, one modulation will be referred to as a chirp, and a group of chirps that are repeatedly transmitted will be referred to as a chirp sequence. The chirp sequence is repeated at a period Tc. FIG. 6 shows an example of a chirp sequence composed of down chirps. In this example, as an example of time-division MIMO, transmission is performed by switching the transmitting antenna between Tx1 and Tx2 for each chirp. Further, the total number of chirps is N in total for the transmitting antennas Tx1 and Tx2.

In FIG. 6, along with the modulation pattern 61, the transmitting antenna and chirp number for transmission by the transmitting changeover switch are shown. In each chirp sequence, the first chirp, that is, the chirp with chirp number 1, transmits a chirp with modulation pattern 61 from transmitting antenna Tx1. In the chirp with chirp number 2, a chirp with modulation pattern 61 is transmitted from the transmitting antenna Tx2. When the chirp number is an odd number, a chirp with a modulation pattern 61 is transmitted from the transmitting antenna Tx1, and when the chirp number is an even number, a chirp with a modulation pattern 61 is transmitted from the transmitting antenna Tx2. In FIG. 6, cases where the chirp numbers are 1, 2, 3, N-2, N-1, and N are shown. Note that the radar device 1 of the first embodiment can be applied without being limited to the various parameters of the chirp sequence such as the chirp slope and modulation width shown in FIG.

With the modulation pattern 61, as described above, the transmission signal is transmitted from the transmission antenna Tx1 and the reception signal received by the reception antennas Rx1, Rx2, Rx3, and Rx4, and the transmission signal is transmitted from the transmission antenna Tx2 and the reception antenna Rx1, It is possible to receive virtual reception channel signals for a total of 8 channels of reception signals received by Rx2, Rx3, and Rx4. As shown in FIG. 7, the virtual reception channels are virtual reception channels VRC1, VRC2, VRC3, VRC4, VRC5, VRC6, VRC7, and VRC8 corresponding to virtual reception antennas VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8. There are a total of 8 channels.

The processing unit 11 measures the distance and relative velocity of the target object 33 in the FCM method using the data of eight virtual reception channels as input. The principle of measuring distance and relative velocity in the FCM method is a known technique as described in Patent Document 2. The operation of the processing section 11 will be described below using FIG. 8. FIG. 8 is a flowchart showing the flow of processing performed by the processing unit 11 to measure the distance, relative velocity, and angle of the target object. However, FIG. 8 is an example, and the radar device 1 of the first embodiment is not limited to the signal processing method shown in FIG. 8.

First, in step ST1, the processing unit 11 performs frequency conversion processing by inputting the data of the eight obtained virtual reception channels VRC1 to VRC8 (frequency conversion processing step). Here, a description will be given assuming that two-dimensional FFT (Fast Fourier Transform) is used as the frequency conversion process, for example, as described in Patent Document 2.

Specifically, the first FFT process is performed on the data of each chirp in FIG. 6 to generate a power spectrum. Next, the processing results are collected for each frequency bin over all chirps, and a second FFT processing is performed. Here, the frequency of the beat signal detected at each chirp by the transmission signal reflected by the same target object 33, that is, the frequency of the component that becomes the peak in the power spectrum, is the same.

However, if the target object 33 and the vehicle on which the radar device 1 is mounted have a relative speed, the phase of the beat signal will differ slightly for each chirp. In other words, in the result of the second FFT process, the power spectrum whose frequency components corresponding to the rotational speed of the phase are frequency bins, i.e., speed bins, is different from the frequency bins obtained as a result of the first FFT process, i.e., It will be calculated for each distance bin. Hereinafter, the power spectrum obtained by the second FFT process will be referred to as a two-dimensional power spectrum.

Next, in step ST2, the processing unit 11 detects a peak by extracting the peak from the two-dimensional power spectrum (peak detection step). Examples of methods for detecting peaks include the well-known CFAR (Constant False Alarm). Alternatively, as another method, for example, a frequency bin that exceeds a preset threshold value and has a local maximum value may be extracted from the frequency bins, or a method that can detect the reflection from the target object. Any method is fine.

Further, data of virtual reception channels VRC1 to VRC8 may be added before peak detection. For example, the peak may be detected after adding and averaging the amplitude values of eight virtual reception channels, or the beam may be directed in a preset direction using well-known DBF (Digital Beam Forming) processing. It is also possible to detect the peak after that.

Next, in step ST3, the processing unit 11 calculates the distance and relative velocity of the target object 33 with respect to the detected peak based on the principle of a known FCM method as described in Patent Document 2, for example. speed calculation process). Note that in the first embodiment, the method of calculating the distance and relative velocity of the target object is not limited to this case, and any method may be used.

Next, in step ST4, the processing unit 11 measures the angle of the target object 33 (angle measurement process). There are various angle measurement methods, such as a beamformer method, a super-resolution angle measurement method, and a maximum likelihood estimation method, and the first embodiment does not limit the angle measurement method. Here, the case where angle measurement is performed using the above-mentioned phase monopulse method will be explained as an example.

For example, between all the reception channels where the distance between the virtual reception channels in FIG. Phase monopulse angle measurement is performed according to equation (2) for the signals of the virtual reception channels in seven intervals: 1, 2, 3, 3, 3, 3, 3, 4, and 4. The average value of the seven angles thus obtained is determined, and the average value is output as the angle of the target object 33.

By the above method, the processing unit 11 calculates the distance, relative velocity, and angle of the target object 33 in the radar device 1. As shown in FIG. 6, by executing the process flow for each chirp sequence repeated at a preset time interval (period Tc), the distance, relative velocity, and angle of the target object 33 can be determined. , is calculated repeatedly at the time interval.

Detection results such as the distance, relative speed, and angle of the target object 33 obtained by the radar device 1 are transmitted to the ECU 2 of the vehicle. The ECU 2 of the vehicle uses the detection results to control various vehicle applications.

In addition, in the processing unit 11, time-series processing, so-called tracking processing, etc., is used to calculate correlations in time-series, and smooth detection results such as distance, relative velocity, and angle in time-series. Processing may be performed to smooth out errors in the detection results.

In the first embodiment, the case of the time division MIMO method has been described as an example, but other methods may be used as long as the signals from the transmitting antennas Tx1 and Tx2 can be separated. For example, there are methods of transmitting using transmitting antennas Tx1 and Tx2 at different transmitting frequencies, methods of transmitting by multiplying orthogonal codes between transmitting antennas Tx1 and Tx2, and methods of separating signals of transmitting antennas Tx1 and Tx2. A method etc. may be applied.

The radar device 1 of Embodiment 1 includes a first antenna group Gr1 having a plurality of first antennas arranged at an antenna interval D1 of a predetermined distance d, and an arbitrary number of first antennas of two or more and a reverse antenna group Gr1. A second antenna group Gr2 having a second antenna in operation is provided, and the first antenna is used to interpolate between the second antennas, which are wider than the distance d, so that they are arranged at equal intervals of a distance d. Since the virtual reception antenna group 50 having a plurality of virtual reception antennas VR is provided, even if antennas of three or more channels cannot be physically arranged at equal intervals of distance d by the feeder circuit 25, the side Lobes can be reduced and false detections can be suppressed. In the radar device 1 of the first embodiment, since the adjacent virtual receiving antennas VR are arranged at a distance d, side lobes can be reduced and false detection can be suppressed. As shown in the receiving antenna Rx of FIG. 3 , if the feeding circuit 25 is present in the horizontal direction (adjacent direction) of the antenna, it is not possible to physically arrange antennas with three or more channels at equal intervals of distance d. . Therefore, the radar device 1 of the first embodiment applies MIMO or the like to realize a virtual reception antenna group 50 having a plurality of virtual reception antennas VR configured to be arranged at equal intervals of distance d. The arrangement method of the first antenna group Gr1 and the second antenna group Gr2 was devised.

The radar device 1 of the first embodiment realizes a broadband antenna frequency characteristic with a ratio band of 2% or more and 10% or less by using a parallel feeding method for the antenna feeding circuit 25. It is physically impossible to arrange antennas with three or more channels at equal intervals of distance d. However, the radar device 1 of Embodiment 1 includes a set of first antennas At1 including two first antennas At1 arranged at an interval of a distance d, and arranged at an interval twice the distance d. Since the virtual reception antenna group 50 is equipped with a plurality of second antennas At2 and has a plurality of virtual reception antennas VR configured to be arranged at equal intervals of a distance d by applying MIMO or the like, a broadband antenna frequency can be achieved. It is possible to reduce sidelobes and suppress false detections while maintaining the characteristics. An antenna that achieves broadband antenna frequency characteristics is a broadband antenna.

The radar device 1 of the first embodiment including the transmitting antenna Tx and the receiving antenna Rx arranged in the first example of the antenna arrangement is the radar device 1 of the first embodiment including the antenna of the first example of the antenna arrangement. be. The radar device 1 of the first embodiment including the antenna of the first example of antenna arrangement has a first antenna group having a plurality of first antennas, that is, transmitting antennas Tx arranged at an antenna interval D1 of a predetermined distance d. Gr1, and a second antenna group Gr2 having an arbitrary number of two or more second antennas, that is, receiving antennas Rx, which operate inversely to the first antenna, and between each second antenna whose interval is wider than the distance d. Since the virtual receiving antenna group 50 includes a plurality of virtual receiving antennas VR configured to be arranged at equal intervals of a distance d by interpolation with the antenna, the feeding circuit 25 physically arranges them at equal intervals of a distance d. Even in cases where it is not possible to arrange antennas with three or more channels, side lobes can be reduced and false detections can be suppressed. The antenna spacing D1 in the first example of antenna arrangement is the transmitting antenna spacing Dtx.

In the first example of the antenna arrangement shown in FIGS. 3 and 4, the first antenna of the first antenna group Gr1 is the transmitting antenna Tx, and the second antenna of the second antenna group Gr2 is the receiving antenna Rx. However, as shown in FIGS. 9 and 10, the first antenna of the first antenna group Gr1 may be the receiving antenna Rx, and the second antenna of the second antenna group Gr2 may be the transmitting antenna Tx. In the second example of the antenna arrangement shown in FIGS. 9 and 10, the number of transmitting antennas Tx is four and the number of receiving antennas Rx is two. In the radar apparatus 1 equipped with the antenna of the second example of antenna arrangement, the transmission changeover switch 124 of the transmission circuit 12 is configured to switch among the transmission antennas Tx1, Tx2, Tx3, and Tx4. Further, the receiving circuit 13 includes mixers 131 and 132, filter circuits 141 and 142, and analog-to-digital converters 151 and 152, which correspond to the receiving antennas Rx1 and Rx2. The modulation pattern 61 is a pattern that repeats in the order of Tx1, Tx2, Tx3, and Tx4. FIG. 11 shows a virtual receiving antenna group 50 formed by transmitting antennas Tx and receiving antennas Rx in a second example of antenna arrangement. Eight virtual receiving antennas VR1 to VR8 are formed by the two receiving antennas Rx1 and Rx2 and the four transmitting antennas Tx1, Tx2, Tx3, and Tx4.

The receiving antenna Rx1 includes a plurality of element antennas 19 arranged along a phase center line 27a passing through the phase center Cr1. The receiving antenna Rx2 includes a plurality of element antennas 19 arranged along a phase center line 27b passing through the phase center Cr2. A plurality of element antennas 19 of the receiving antenna Rx are arranged along a phase center line passing through the phase center. Similarly to the receiving antenna Rx, the transmitting antennas Tx1, Tx2, Tx3, and Tx4 are arranged along a phase center line in which each of the plurality of element antennas 19 passes through the phase center. The transmitting antenna Tx1 includes a plurality of element antennas 19 arranged along a phase center line 28a passing through the phase center Ct1, and the transmitting antenna Tx2 is arranged along a phase center line 28b passing through the phase center Ct2. A plurality of element antennas 19 are provided. The transmitting antenna Tx3 includes a plurality of element antennas 19 arranged along the phase center line 28c passing through the phase center Ct3, and the transmitting antenna Tx4 is arranged along the phase center line 28d passing through the phase center Ct4. A plurality of element antennas 19 are provided. The direction in which the phase center line of each of the transmitting antenna Tx and the receiving antenna Rx extends is also the direction in which the plurality of element antennas 19 extend.

The transmitting antennas Tx are arranged in parallel on the surface of the substrate 23 so that they are parallel to each other, that is, so that the phase center lines 28a to 28d are parallel to each other, and the receiving antennas Rx are arranged parallel to each other, that is, so that the phase center lines 28a to 28d are parallel to each other. , 27b are arranged in parallel on the surface of the substrate 23. The reception antenna interval Drx between the two reception antennas Rx1 and Rx2, that is, the interval between the phase center line 27a and the phase center line 27b, is equal to the distance d. The spacing Dtx between adjacent transmitting antennas Tx1, Tx2, Tx3, and Tx4 is twice the distance d, that is, 2d. In the second example of the antenna arrangement shown in FIG. 10, the reception antenna interval Drx is equal to the distance d, so the reception antennas Rx1 and Rx2 are the antennas of the first antenna group Gr1. Further, since the transmitting antenna spacing Dtx is twice the distance d, that is, 2d, the transmitting antennas Tx1 to Tx4 are the antennas of the second antenna group Gr2.

The receiving antennas Rx are arranged in a line in a first arrangement direction dr1, and the transmitting antennas Tx are arranged in a line in a second arrangement direction dr2. The first arrangement direction dr1 is a direction perpendicular to the phase center lines 27a, 27b, and the second arrangement direction dr2 is a direction perpendicular to the phase center lines 28a to 28d. FIG. 10 shows an example in which the phase centers Ct1 to Ct4 of the transmitting antenna Tx and the phase centers Cr1 and Cr2 of the receiving antenna Rx are arranged on the same axis. The receiving antennas Rx1 and Rx2 are arranged in order toward the positive side in the first arrangement direction dr1, and the transmitting antennas Tx1, Tx2, Tx3, and Tx4 are arranged in order toward the positive side in the second arrangement direction dr2.

In the example of FIG. 11, the virtual receiving antennas VR1 to VR8 are arranged in the order of VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8 toward the positive side in the third arrangement direction dr3. Become. Among these virtual receiving antenna groups 50, VR1, VR3, VR5, and VR7 indicated by solid circles are virtual receiving antennas formed by signals transmitted by transmitting antennas Tx1 to Tx4 and received by receiving antenna Rx1, VR2, VR4, VR6, and VR8 indicated by broken line circles are virtual receiving antennas formed by signals transmitted by the transmitting antennas Tx1 to Tx4 and received by the receiving antenna Rx2.

The radar device 1 of the first embodiment including the transmitting antenna Tx and the receiving antenna Rx arranged in the second example of the antenna arrangement is the radar device 1 of the first embodiment including the antenna of the second example of the antenna arrangement. be. The radar device 1 of the first embodiment including the antenna of the second example of antenna arrangement has a first antenna group having a plurality of first antennas, that is, receiving antennas Rx arranged at an antenna interval D1 of a predetermined distance d. Gr1, and a second antenna group Gr2 having an arbitrary number of two or more second antennas, that is, transmitting antennas Tx, which operate inversely to the first antenna. Since the virtual receiving antenna group 50 includes a plurality of virtual receiving antennas VR configured to be arranged at equal intervals of a distance d by interpolation with the antenna, the feeding circuit 25 physically arranges them at equal intervals of a distance d. Even in cases where it is not possible to arrange antennas with three or more channels, side lobes can be reduced and false detections can be suppressed. The antenna spacing D1 in the second example of antenna arrangement is the receiving antenna spacing Drx.

As described in the first and second examples of antenna arrangement, the plurality of first antennas arranged at antenna intervals D1 of a predetermined distance d may be either the transmitting antenna Tx or the receiving antenna Rx. As described above, FIG. 12 shows a third example of antenna arrangement in which the first antenna and the second antenna are not specified as the transmitting antenna Tx and the receiving antenna Rx. The first antennas At1a and At1b of the first antenna group Gr1 are arranged with an antenna interval D1 of a predetermined distance d. Four second antennas At2a, At2b, At2c, and At2d, which operate in reverse to the first antenna, are arranged at an antenna spacing D2 of twice the distance d, that is, 2d. The antenna spacing D1 is the antenna spacing between adjacent first antennas. The antenna spacing D2 is the antenna spacing between adjacent second antennas. The radar device 1 equipped with the antenna of the third example of antenna arrangement has the configuration shown in FIG. 1 when the first antenna is the transmitting antenna Tx, and when the first antenna is the receiving antenna Rx, the antenna It has the same configuration as the radar device 1 equipped with the antenna of the second example of arrangement.

A virtual reception antenna group 50 formed by the first antenna At1 and the second antenna At2 in a third example of antenna arrangement is shown in FIGS. 13 and 14. The virtual receiving antenna group 50 shown in FIG. 13 is a case in which the first antenna At1 is a transmitting antenna Tx, and the virtual receiving antenna group 50 shown in FIG. 14 is a case in which the first antenna At1 is a receiving antenna Rx. The modulation pattern 61 when the first antenna At1 is the transmitting antenna Tx is a pattern that repeats in the order of Tx1 and Tx2. The modulation pattern 61 when the first antenna At1 is the receiving antenna Rx is a pattern that repeats in the order of Tx1, Tx2, Tx3, and Tx4.

The first antenna At1a includes a plurality of element antennas 19 arranged along a phase center line 31a passing through the phase center C1a. The first antenna At1b includes a plurality of element antennas 19 arranged along a phase center line 31b passing through the phase center C1b. A plurality of element antennas 19 of the first antenna At1 are arranged along a phase center line passing through the phase center. Similarly to the first antenna At1, the second antennas At2a, At2b, At2c, and At2d are also arranged along a phase center line in which each of the plurality of element antennas 19 passes through the phase center. The second antenna At2a includes a plurality of element antennas 19 arranged along the phase center line 32a passing through the phase center C2a, and the second antenna At2b is arranged along the phase center line 32b passing through the phase center C2b. It is equipped with a plurality of element antennas 19. The second antenna At2c includes a plurality of element antennas 19 arranged along the phase center line 32c passing through the phase center C2c, and the second antenna At2d is arranged along the phase center line 32d passing through the phase center C2d. It is equipped with a plurality of element antennas 19. The direction in which the phase center line of each of the first antenna At1 and the second antenna At2 extends is also the direction in which the plurality of element antennas 19 extend.

As shown in FIG. 12, the first antennas At1 are arranged on the surface of the substrate 23 so that they are parallel to each other, that is, so that their phase center lines are parallel. The arrangement direction of the first antenna At1 is the first arrangement direction dr1. The first arrangement direction dr1 is a direction perpendicular to the phase center lines 31a and 31b. The antenna interval D1 between the two first antennas At1a and first antenna At1b, that is, the interval between the phase center line 31a and the phase center line 31b, is equal to the distance d.

Further, as shown in FIG. 12, the second antennas At2 are arranged in parallel on the surface of the substrate 23 so that they are parallel to each other, that is, so that their phase center lines are parallel. The arrangement direction of the second antenna At2 is the second arrangement direction dr2. The second arrangement direction dr2 is a direction perpendicular to the phase center lines 32a to 32d . The first arrangement direction dr1 and the second arrangement direction dr2 are parallel to each other. FIG. 12 shows an example in which the phase centers C1a, C1b of the first antenna At1 and the phase centers C2a, C2b, C2c, C2d of the second antenna At2 are arranged on the same axis. The first antennas At1a and At2a are arranged in order toward the positive side in the first arrangement direction dr1, and the second antennas At2a, At2b, At2c, and At2d are arranged in order toward the positive side in the second arrangement direction dr2. There is.

In the example of FIG. 13, virtual receiving antennas VR1 to VR8 are arranged in the order of VR1, VR5, VR2, VR6, VR3, VR7, VR4, and VR8 toward the positive side in the third arrangement direction dr3. Become. Among these virtual receiving antenna groups 50, VR1, VR2, VR3, and VR4 indicated by solid circles transmit using the first antenna At1a as a transmitting antenna, and the second antennas At2a, At2b, At2c, and At2d as receiving antennas. VR5, VR6, VR7, and VR8 indicated by broken line circles transmit with the first antenna At1b as a transmitting antenna, and the second antennas At2a and At2b as receiving antennas. , At2c, and At2d.

In the example of FIG. 14, virtual receiving antennas VR1 to VR8 are arranged in the order of VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8 toward the positive side in the third arrangement direction dr3. Become. Among these virtual receiving antenna groups 50, VR1, VR3, VR5, and VR7 indicated by solid circles transmit using the second antennas At2a to At2d as transmitting antennas, and receive using the first antenna At1a as a receiving antenna. VR2, VR4, VR6, and VR8 indicated by broken circles are virtual receiving antennas formed by signals, which are transmitted by second antennas At2a to At2d as transmitting antennas, and received by first antenna At1b as a receiving antenna. It is a virtual receiving antenna formed by the signal.

The radar device 1 of the first embodiment including the first antenna At1 and the second antenna At2 arranged in the third example of the antenna arrangement is the radar device of the first embodiment including the antenna of the third example of the antenna arrangement. It is 1. The radar device 1 of the first embodiment equipped with the antenna of the third example of antenna arrangement has a first antenna At1 that is a plurality of transmitting antennas or receiving antennas arranged at an antenna interval D1 of a predetermined distance d. It includes a first antenna group Gr1 and a second antenna group Gr2 having an arbitrary number of two or more second antennas At1 and a second antenna At2 that operate inversely to the first antenna At1, and the first antenna At1 interpolates between the widely spaced second antennas. Since the virtual reception antenna group 50 has a plurality of virtual reception antennas VR configured to Even in the case where the detection error occurs, side lobes can be reduced and false detections can be suppressed.

In a case where the number of channels of the first antenna At1, that is, the number of antennas, is limited to 2, the first antenna At1 is a transmitting antenna Tx having a transmitting function, and the second antenna At2 is a receiving antenna Rx having a receiving function. It is preferable to apply the first example of the antenna arrangement. The reason is as follows.

When the second antenna At2 is the transmitting antenna Tx, that is, in the second example of antenna arrangement, the number of transmitting antennas Tx is greater than the number of receiving antennas Rx. The larger the number of transmitting antennas Tx, the larger the scale of the transmitting circuit 12 within the radar device 1. The transmitting circuit 12, which is a circuit having a function of transmitting radio waves, tends to generate a larger amount of heat than the receiving circuit 13. When the number of channels of the first antenna At1, that is, the number of antennas is limited to 2, and the number of channels, that is, the number of antennas of the second antenna At2 is larger than the first antenna At1, heat generation can be achieved by using the first antenna At1 as the transmitting antenna Tx. It is possible to realize a radar device 1 with a small amount.

Although an example of a parallel feeding system in which the feeding circuit 25 for the transmitting antenna Tx and the receiving antenna Rx is formed so that the wiring lengths to each element antenna 19 are equal has been described, the feeding circuit 25 is not limited to this. FIGS. 15 to 20 show antennas of first to sixth examples. The feeding circuit 25a in the first example of the antenna shown in FIG. 15 is a feeding circuit of a parallel feeding type. The first example of the antenna shown in FIG. 15 includes four element antennas 19 and a feeding circuit 25a. The second example of the antenna shown in FIG. 16 includes four element antennas 19 and a feeding circuit 25b, and the third example of the antenna shown in FIG. 17 includes four element antennas 19 and a feeding circuit 25c. There is. The fourth example of the antenna shown in FIG. 18 includes eight element antennas 19 and a feeding circuit 25d. The fifth example of the antenna shown in FIG. 19 includes four element antennas 19 and a feeding circuit 25e. The sixth example of the antenna shown in FIG. 20 includes four element antennas 19 and a feeding circuit 25f. The symbol 25 is used for the power supply circuit in general, and 25a, 25b, 25c, 25d, 25e, and 25f are used for distinction.

In the feeding circuit 25a of the first example of the antenna shown in FIG. 15, the connecting portion of the element antenna 19 is the first arrangement direction dr1 of the first antenna At1 of the first antenna group Gr1 or the second antenna At2 of the second antenna group Gr2. In this example, the second arrangement direction dr2 is parallel to the second arrangement direction dr2. Since the extending direction of the plurality of element antennas 19 is perpendicular to the first arrangement direction dr1 or the second arrangement direction dr2, the feeding circuit 25a of the first example of the antenna shown in FIG. It can also be said that it is perpendicular to the extending direction of the element antenna 19. The second example of the feeding circuit 25b of the antenna shown in FIG. The third example of the feeding circuit 25c of the antenna shown in FIG. Similarly to the first example, the second and third examples of the antenna are of a parallel feeding type in which the wiring lengths to each element antenna 19 are formed to be equal. The radar device 1 of the first embodiment equipped with the second and third examples of antennas can be used even when receiving antennas or transmitting antennas of three or more channels cannot be physically arranged at intervals of a predetermined distance d. , it is possible to reduce sidelobes and suppress false detections.

Further, although the shape of the element antenna 19 is expressed as a rectangle, the shape of the element antenna 19 may be any shape. As in the fourth example of the antenna shown in FIG. 18, the number of antenna rows constituting one channel may be increased to two or more. FIG. 18 shows an example in which two sets including eight element antennas 19 and a feeder circuit 25d, each having four element antennas 19, extend in a direction perpendicular to the first arrangement direction dr1 or the second arrangement direction dr2. Indicated.

The radar device 1 of the first embodiment is an example in which two first antennas At1 are arranged at intervals of a predetermined distance d, forming a set. . The radar device 1 of embodiments 2 to 6 described later and the radar device 1 equipped with antennas arranged in the seventh example of antenna arrangement shown in FIG. 25 have first antennas arranged at intervals of a predetermined distance d. This is an example in which two At1's form one set, and a plurality of first antenna At1's are provided. Therefore, the radar device 1 of Embodiment 1 and the radar device 1 of Embodiments 2 to 6 are examples in which transmitting antennas Tx or receiving antennas Rx are not physically arranged at intervals of a predetermined distance d for three or more channels. be. In this case, in order to realize a wideband antenna with a fractional band of 2% or more and 10% or less, for example, it is not necessary to use a complete tournament type power supply circuit, that is, a parallel power supply circuit such as the power supply circuits 25a, 25b, and 25c. The feeder circuit 25e of the fifth example of the antenna shown in FIGS. 19 and 20 and the feeder circuit 25f of the sixth example of the antenna may be used. Even in cases where the feed lines to all the element antennas 19 are not of equal length, as in the fifth and sixth antenna examples shown in FIGS. 19 and 20, the desired antenna characteristics can be achieved in the necessary fractional band. If possible, even if it is not possible to physically line up three or more channels of receiving antennas or transmitting antennas at predetermined distance intervals, it will reduce sidelobes and suppress false detections while ensuring the necessary fractional bandwidth. can do. The desired antenna characteristics are antenna characteristics set by design, that is, designed antenna characteristics.

The first arrangement direction dr1, the second arrangement direction dr2, and the third arrangement direction dr3 indicate the arrangement direction of adjacent antennas, not the direction between the phase centers. For example, as in the fourth example of antenna arrangement shown in FIG. 21, some of the plurality of antennas may be shifted in the extending direction of the element antenna 19. FIG. 21 shows an example in which the receiving antennas Rx1 and Rx2 in the first antenna group Gr1 are shifted from each other in the extending direction of the element antenna 19 or in the extending direction of the phase center line. The radar device 1 including the first antenna group Gr1 and the second antenna group Gr2 arranged in the fourth example of the antenna arrangement shown in FIG. 21 has a first arrangement direction dr1, a second arrangement direction dr2, and a third arrangement direction. The angle of the target object 33 can be measured not only in dr3 but also in the direction in which the phase center line of the antenna extends perpendicular to dr3. The radar device 1 equipped with the antenna of the fourth example of the antenna arrangement shown in FIG. 21 has the same configuration as the radar device 1 equipped with the antenna of the second example of the antenna arrangement, except for the antenna arrangement.

FIG. 22 shows a virtual reception antenna group 50 formed by the transmission antenna Tx and reception antenna Rx in the fourth example of the antenna arrangement shown in FIG. 21. The fourth example of the antenna arrangement differs from the second example of the antenna arrangement shown in FIG. They are different in that they are Therefore, in the virtual receiving antenna group 50 formed by the fourth example of antenna arrangement, the virtual receiving antennas VR2, VR4, VR6, and VR8 indicated by broken line circles are shifted in the direction in which the phase center lines of the antennas extend. The direction of the phase center lines 27a and 27b in FIG. 21 from the top to the bottom of the paper is defined as the positive side in the extending direction of the phase center lines. Since the receiving antenna Rx2 is shifted from the receiving antenna Rx1 to the positive side in the extending direction of the phase center line, the virtual receiving antenna group 50 also includes virtual receiving antennas VR2 and VR4 formed by the signal received by the receiving antenna Rx2. , VR6, and VR8 are shifted to the positive side in the extending direction of the phase center line from the virtual receiving antennas VR1, VR3, VR5, and VR7 formed by the signals received by the receiving antenna Rx1.

The radar device 1 of the first embodiment including the transmitting antenna Tx and the receiving antenna Rx arranged in the fourth example of the antenna arrangement shown in FIG. 21 is the first embodiment including the antenna of the fourth example of the antenna arrangement. This is a radar device 1. The radar device 1 of the first embodiment including the antenna of the fourth example of the antenna arrangement has a first antenna group having a plurality of first antennas, that is, receiving antennas Rx arranged at an antenna interval D1 of a predetermined distance d. Gr1, and a second antenna group Gr2 having an arbitrary number of two or more second antennas, that is, transmitting antennas Tx, which operate inversely to the first antenna. Since the virtual receiving antenna group 50 includes a plurality of virtual receiving antennas VR configured to be arranged at equal intervals of a distance d by interpolation with the antenna, the feeding circuit 25 physically arranges them at equal intervals of a distance d. Even in cases where it is not possible to arrange antennas with three or more channels, side lobes can be reduced and false detections can be suppressed.

The radar device 1 may include antennas other than the first antenna group Gr1 and the second antenna group Gr2. In the fifth example of the antenna arrangement shown in FIG. 23, the first antenna group Gr1 and the second antenna group Gr2 of the second example of the antenna arrangement shown in FIG. This is an example. For example, when detecting a long distance, the antenna for detecting the long distance does not necessarily have to be a broadband antenna. Therefore, for long distance applications, conventional narrow band antennas such as transmitting antenna FTx and receiving antennas FRx1 and FRx2 can be used. The radar device 1 equipped with the antenna of the fifth example of the antenna arrangement shown in FIG. , and a receiving circuit. The radar apparatus 1 equipped with the transmitting antenna Tx, the receiving antenna Rx, the transmitting antenna FTx, the receiving antennas FRx1, and FRx2 arranged in the fifth example of the antenna arrangement shown in FIG. The target object 33 can be detected. Since the radar device 1 equipped with the antenna of the fifth example of the antenna arrangement includes the radar device 1 of the first embodiment equipped with the antenna of the second example of the antenna arrangement, the antenna of the second example of the antenna arrangement is The same effects as the radar device 1 of Embodiment 1 provided therein are achieved.

The sixth example of the antenna arrangement shown in FIG. 24 is an example in which the first antenna group Gr1, the second antenna group Gr2, and the transmitting antenna Tx5 of the second example of the antenna arrangement shown in FIG. 10 are arranged. In FIG. 24, an example in which the receiving antennas Rx1 and Rx2 of the first antenna group Gr1 are arranged on the surface of the substrate 23b, and the transmitting antennas Tx1 to Tx4 and the transmitting antenna Tx5 of the second antenna group Gr2 are arranged on the surface of the substrate 23a. showed that. The radar device 1 equipped with the antenna of the sixth example of the antenna arrangement shown in FIG. It is configured to switch between transmitting antennas Tx1, Tx2, Tx3, Tx4, and Tx5. The transmitting antenna Tx5 includes a plurality of element antennas 19 arranged along a phase center line 28e passing through the phase center Ct5. In FIG. 24, an example is shown in which the transmitting antenna interval Dtxa between the transmitting antenna Tx5 and the transmitting antenna Tx4 of the adjacent second antenna group Gr2 is longer than the transmitting antenna interval Dtx. Since the radar device 1 equipped with the antenna of the sixth example of antenna arrangement includes the radar device 1 of Embodiment 1 equipped with the antenna of the second example of antenna arrangement, the antenna of the second example of antenna arrangement is The same effects as the radar device 1 of Embodiment 1 provided therein are achieved.

A plurality of antennas of the first antenna group Gr1 and the second antenna group Gr2 may be arranged in the extending direction of the phase center line. The seventh example of the antenna arrangement shown in FIG. 25 corresponds to the antenna arrangement including two sets of the first antenna group Gr1 and the second antenna group Gr2 of the first example of the antenna arrangement shown in FIG. The first antenna group Gr1 includes four transmitting antennas Tx1, Tx2, Tx3, and Tx4, and the second antenna group Gr2 includes eight receiving antennas Rx1, Rx2, Rx3, Rx4, Rx5, Rx6, Rx7, Equipped with Rx8. The transmitting antenna Tx includes a pair of antennas whose antenna spacing is less than or equal to the distance d, and the receiving antenna Rx does not include a pair of antennas whose antenna spacing is less than or equal to the distance d. The transmitting antennas Tx1 and Tx2 constitute a first antenna group 22a, and the transmitting antennas Tx3 and Tx4 constitute a first antenna group 22b. Receiving antennas Rx1 to Rx4 constitute a second antenna group 24a, and receiving antennas Rx5 to Rx8 constitute a second antenna group 24b. The first antenna group 22b and the second antenna group 24b are a first example of the antenna arrangement shown in FIG. The first antenna group 22a and the second antenna group 24a have an antenna arrangement in which the transmitting antenna Tx and the receiving antenna Rx in the first example of the antenna arrangement shown in FIG. 4 are shifted in the direction in which the phase center line extends.

In addition, in FIG. 25, there is one first antenna group arranged in the first arrangement direction dr1 of the first antenna group Gr1, and one second antenna group arranged in the second arrangement direction dr2 of the second antenna group Gr2. An example is shown in which there is one. However, there are two or more first antenna sets arranged in the first arrangement direction dr1 of the first antenna group Gr1, and two or more second antenna sets arranged in the second arrangement direction dr2 of the second antenna group Gr2. In some cases, it is more than that. In such a case, the first antenna group Gr1 has the same configuration as the A group having a plurality of first antennas At1 arranged in the first arrangement direction dr1, and It can also be said to include a B group arranged in a fourth arrangement direction dr4, which is a perpendicular direction. In the case of FIG. 25, group A is the first antenna group 22a, and group B is the first antenna group 22b. Further, the second antenna group Gr2 has the same configuration as the C group having a plurality of second antennas At2 arranged in the second arrangement direction dr2, and is directed in a direction perpendicular to the second arrangement direction dr2. It can also be said that the D group is arranged in the fifth arrangement direction dr5. In the case of FIG. 25, group C is the second antenna group 24a, and group D is the second antenna group 24b.

The radar apparatus 1 equipped with the antenna of the seventh example of the antenna arrangement shown in FIG. 25 is configured such that the transmission changeover switch 124 of the transmission circuit 12 switches among the transmission antennas Tx1, Tx2, Tx3, and Tx4. The receiving circuit 13 also includes eight mixers 131, eight filter circuits 141, and eight analog-to-digital converters 151 corresponding to receiving antennas Rx1, Rx2, Rx3, Rx4, Rx5, Rx6, Rx7, and Rx8. It is configured with the following. The radar device 1 equipped with the antenna of the seventh example of antenna arrangement transmits a transmission signal having a modulation pattern 61 that repeats in the order of Tx1, Tx2, Tx3, and Tx4.

The transmitting antennas Tx1 and Tx3 include a plurality of element antennas 19 arranged along a phase center line 28a, and the transmitting antennas Tx2 and Tx4 include a plurality of element antennas 19 arranged along a phase center line 28b. There is. The receiving antennas Rx1 and Rx5 include a plurality of element antennas 19 arranged along a phase center line 27a, and the receiving antennas Rx2 and Rx6 include a plurality of element antennas 19 arranged along a phase center line 27b. There is. The receiving antennas Rx3 and Rx7 include a plurality of element antennas 19 arranged along a phase center line 27c, and the receiving antennas Rx4 and Rx8 include a plurality of element antennas 19 arranged along a phase center line 27d. There is. The transmitting antennas Tx1, Tx3 and the transmitting antennas Tx2, Tx4 are arranged side by side on the surface of the substrate 23 so that they are parallel to each other, that is, so that their phase center lines are parallel to each other. The receiving antennas Rx1 and Rx5, the receiving antennas Rx2 and Rx6, the receiving antennas Rx3 and Rx7, and the receiving antennas Rx4 and Rx8 are arranged on the surface of the substrate 23 so that they are parallel to each other, that is, so that their phase center lines are parallel to each other. are placed side by side.

The transmitting antennas Tx1 and Tx2 in the first antenna group 22a are arranged in the first arrangement direction dr1, and the transmitting antennas Tx3 and Tx4 in the first antenna group 22b are arranged in the first arrangement direction dr1. The receiving antennas Rx1 to Rx4 in the second antenna group 24a are arranged in the second arrangement direction dr2, and the receiving antennas Rx5 to Rx8 in the second antenna group 24b are arranged in the second arrangement direction dr2. In FIG. 25, an example is shown in which the phase centers of the receiving antennas Rx5 to Rx8 in the second antenna group 24b and the phase centers of the transmitting antennas Tx3 and Tx4 in the first antenna group 22b are arranged on the same axis as the broken line 29a. Indicated. The first antenna group 22a and the first antenna group 22b are arranged in order toward the positive side of the fourth arrangement direction dr4 perpendicular to the first arrangement direction dr1. The second antenna group 24a and the second antenna group 24b are arranged in order toward the positive side of the fifth arrangement direction dr5 perpendicular to the second arrangement direction dr2. The phase centers of the transmitting antennas Tx1 and Tx2 in the first antenna group 22a are arranged on the same axis, which is a broken line 29b. The phase centers of the receiving antennas Rx1 to Rx4 of the second antenna group 24a are arranged on the same axis, which is a broken line 29c. Dashed lines 29a, 29b, and 29c are parallel to each other.

The transmission antenna interval Dtx between the transmission antenna Tx1 and the transmission antenna Tx2 in the first antenna group 22a, the transmission antenna interval Dtx between the transmission antenna Tx3 and the transmission antenna Tx4 in the first antenna group 22b, that is, the phase center line 28a The distance from the phase center line 28b is equal to the distance d. The receiving antenna spacing Drx between adjacent receiving antennas Rx of receiving antennas Rx1 to Rx4 in the second antenna group 24a, the receiving antenna spacing Drx between adjacent receiving antennas Rx of receiving antennas Rx5 to Rx8 in the second antenna group 24b, that is, the phase The distance between adjacent phase center lines of the center lines 27a to 27d is twice the distance d, that is, 2d. The transmission antenna group interval Dtxsv, which is the first antenna group interval between the first antenna group 22a and the first antenna group 22b, is the interval between the broken line 29b and the broken line 29a. The receiving antenna group interval Drxsv, which is the second antenna group interval between the second antenna group 24a and the second antenna group 24b, is the interval between the broken line 29c and the broken line 29a.

FIG. 26 shows a virtual reception antenna group 50 formed by the transmission antenna Tx and reception antenna Rx in the seventh example of the antenna arrangement shown in FIG. In the virtual receiving antenna group 50, 32 virtual receiving antennas VR1 to VR32 are formed by four transmitting antennas Tx1 to Tx4 and eight receiving antennas Rx1 to Rx8. VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8 indicated by solid white circles are virtual receiving antennas formed by signals transmitted by transmitting antenna Tx1 and received by receiving antennas Rx1 to Rx8, and are shown in white. VR9, VR10, VR11, VR12, VR13, VR14, VR15, and VR16 indicated by broken-line circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx2 and received by the receiving antennas Rx1 to Rx8. VR17, VR18, VR19, VR20, VR21, VR22, VR23, and VR24 shown by solid circles with patterns are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx3 and received by the receiving antennas Rx1 to Rx8, VR25, VR26, VR27, VR28, VR29, VR30, VR31, and VR32 indicated by broken line circles with patterns are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx4 and received by the receiving antennas Rx1 to Rx8.

The virtual receiving antenna group 50 shown in FIG. 26 includes a set of eight virtual receiving antennas VR arranged in a third arrangement direction dr3 parallel to the first arrangement direction dr1 and the second arrangement direction dr2. Four sets are arranged in a sixth arrangement direction dr6 perpendicular to . The sixth arrangement direction dr6 is a direction parallel to the fourth arrangement direction dr4 and the fifth arrangement direction dr5. A first set, a second set, a third set, and a fourth set are arranged in order toward the positive side of the sixth arrangement direction dr6. The virtual receiving antennas of the first set of virtual receiving antennas VR1, VR9, VR2, VR10, VR3, VR11, VR4, and VR12 are configured so that the distance Dvr between adjacent virtual receiving antennas is equal to the distance d. Virtual receiving antennas VR1 to VR4 are a first set of virtual receiving antennas formed by signals transmitted by transmitting antenna Tx1 and received by receiving antennas Rx1 to Rx4, and virtual receiving antennas VR9 to VR12 are formed by signals transmitted by transmitting antenna Tx2. This is a first set of virtual receiving antennas formed by signals received by the receiving antennas Rx1 to Rx4.

The second set of virtual receiving antennas VR5, VR13, VR6, VR14, VR7, VR15, VR8, and VR16 are configured so that the distance Dvr between adjacent virtual receiving antennas is equal to the distance d. Virtual receiving antennas VR5 to VR8 are a second set of virtual receiving antennas formed by signals transmitted by transmitting antenna Tx1 and received by receiving antennas Rx5 to Rx8, and virtual receiving antennas VR13 to VR16 are formed by signals transmitted by transmitting antenna Tx2. This is a second set of virtual receiving antennas formed by the signals received by the receiving antennas Rx5 to Rx8. The third set of virtual receiving antennas VR17, VR25, VR18, VR26, VR19, VR27, VR20, and VR28 are configured so that the distance Dvr between adjacent virtual receiving antennas is equal to the distance d. Virtual receiving antennas VR17 to VR20 are a third set of virtual receiving antennas formed by signals transmitted by transmitting antenna Tx3 and received by receiving antennas Rx1 to Rx4, and virtual receiving antennas VR25 to VR28 are formed by signals transmitted by transmitting antenna Tx4. This is a third set of virtual receiving antennas formed by the signals received by the receiving antennas Rx1 to Rx4. The fourth set of virtual receiving antennas VR21, VR29, VR22, VR30, VR23, VR31, VR24, and VR32 are configured such that the distance Dvr between adjacent virtual receiving antennas is equal to the distance d. Virtual receiving antennas VR21 to VR24 are a fourth set of virtual receiving antennas formed by signals transmitted by transmitting antenna Tx3 and received by receiving antennas Rx5 to Rx8, and virtual receiving antennas VR29 to VR32 are formed by signals transmitted by transmitting antenna Tx4. This is a fourth set of virtual receiving antennas formed by the signals received by the receiving antennas Rx5 to Rx8.

The interval between the first set of virtual receiving antennas and the second set of virtual receiving antennas in the sixth arrangement direction dr6 is the receiving antenna group interval Drxsv, and the interval between the third set of virtual receiving antennas and the fourth set of virtual receiving antennas is the receiving antenna group interval Drxsv. The spacing in the sixth arrangement direction dr6 is the receiving antenna group spacing Drxsv. The interval between the first set of virtual receiving antennas and the third set of virtual receiving antennas in the sixth arrangement direction dr6 is the transmitting antenna group interval Dtxsv. The radar device 1 equipped with the antenna of the seventh example of antenna arrangement corresponds to the radar device 1 of Embodiment 1 equipped with two sets of antennas of the first example of antenna arrangement, so the antenna of the first example of antenna arrangement The same effects as the radar device 1 of Embodiment 1 including the above are achieved. Moreover, the radar device 1 equipped with the antenna of the seventh example of antenna arrangement measures the distance, relative velocity, and angle of the target object 33 in two dimensions of the third arrangement direction dr3 and the sixth arrangement direction dr6 perpendicular to this. can be measured.

Since the radar device 1 of the first embodiment cannot physically arrange the first antennas At1 of three or more channels at intervals of a predetermined distance d, the first antennas of two channels physically cannot be arranged at intervals of a predetermined distance d. This is an example in which At1 is arranged. However, in the radar device 1 of the first embodiment, since the plurality of virtual reception antennas VR formed by the transmission and reception of the first antenna At1 and the second antenna At2 can be arranged at equal intervals with a distance d, side lobes can be reduced and errors can be made. Detection can be suppressed.

As described above, the radar device 1 according to the first embodiment includes a plurality of transmitting antennas Tx that radiate a transmitted signal toward the target object 33, and a plurality of transmitting antennas Tx that receive a reflected signal obtained by reflecting the transmitted signal from the target object 33. It includes a plurality of reception antennas Rx that output as reception signals, and a processing section 11 that processes the reception signals output from each of the plurality of reception antennas Rx. The radar device 1 is provided with either a plurality of transmitting antennas Tx or a plurality of receiving antennas Rx, with the antenna interval between adjacent antennas determined based on the field of view required for the radar device 1 as a basic distance (distance d). An antenna group that is an antenna group and includes a first antenna group having a plurality of first antennas At1 in which the antenna spacing D1 between adjacent antennas is a basic distance (distance d) is referred to as a first antenna group Gr1; The antenna group includes a plurality of antennas different from the first antenna At1 of the group Gr1, and includes a plurality of second antennas At2 in which the antenna spacing D2 between adjacent antennas is twice the basic distance (distance d). The antenna group including the second antenna group is referred to as a second antenna group Gr2. The first antenna At1 and the second antenna At2 include a plurality of element antennas 19 and a power feeding circuit 25 that feeds power to the element antennas 19. The plurality of first antennas At1 are arranged in a first arrangement direction dr1 perpendicular to the transmission direction of the transmission signal, and have respective feeding circuits 25 on the positive side or the negative side of the first arrangement direction dr1. . The plurality of second antennas At2 are arranged in a second arrangement direction dr2 that is perpendicular to the transmission direction of the transmission signal and parallel to the first arrangement direction dr1, and the feeding circuit 25 is arranged on the positive side or the negative side of the second arrangement direction dr2. Have it on the side. The feeding circuit 25 is not arranged between adjacent antennas in the first antenna group. A virtual reception antenna group 50 configured of a plurality of virtual reception antennas VR formed by a plurality of first antennas At1 of the first antenna group Gr1 and a plurality of second antennas At2 of the second antenna group Gr2 transmits transmission signals. They are arranged in a third arrangement direction dr3 that is perpendicular to the direction and parallel to the first arrangement direction dr1 and the second arrangement direction dr2. ) is the basic distance (distance d). With this configuration, the radar device 1 of the first embodiment includes a first antenna group Gr1 having a plurality of first antennas At1 in which the antenna spacing D1 between adjacent antennas is a basic distance (distance d). The second antenna group Gr2 includes a second antenna group having a plurality of second antennas At2 in which the antenna interval D2 between adjacent antennas is twice the basic distance (distance d), Since the interval (virtual reception antenna interval Dvr) between adjacent virtual reception antennas VR of the plurality of virtual reception antennas VR formed by transmission and reception of the plurality of second antennas At2 is the basic distance (distance d), the predetermined distance is Even if the first antennas At1, which are the receiving antennas Rx or transmitting antennas Tx of three or more channels, cannot be physically arranged at intervals of d, side lobes can be reduced and false detections can be suppressed.

Embodiment 2.
FIG. 27 is a diagram showing the antenna arrangement of the radar device according to the second embodiment, and FIG. 28 is a diagram showing a virtual reception antenna group corresponding to the antenna arrangement of FIG. 27. In the radar device 1 of the first embodiment, an example has been described in which the first antenna group Gr1 includes only one antenna set of two antennas in the first arrangement direction dr1. The radar device 1 of the second embodiment is an example in which the first antenna group Gr1 includes a plurality of two antenna groups in the first arrangement direction dr1. The parts that are different from the radar device 1 of Embodiment 1 will be mainly explained. The radar device 1 of the second embodiment equipped with the antenna arrangement shown in FIG. , a receiving circuit 13, and a processing section 11. The radar device 1 equipped with an antenna having the antenna arrangement shown in FIG. 27 transmits a transmission signal having a modulation pattern 61 that repeats in the order of Tx1 and Tx2.

The transmitting antenna Tx and receiving antenna Rx will be explained. In the antenna arrangement shown in FIG. 27, the receiving antenna Rx is the antenna of the first antenna group Gr1, that is, the first antenna At1, and the transmitting antenna Tx is the antenna of the second antenna group Gr2, that is, the second antenna At2. The receiving antennas Rx1, Rx2, RX3, and RX4 are arranged in order toward the positive side in the first arrangement direction dr1, and the transmitting antennas Tx1 and Tx2 are arranged in order toward the positive side in the second arrangement direction dr2. The receiving antennas Rx1 and Rx2 have a receiving antenna spacing Drx, that is, the spacing between the phase center line 27a and the phase center line 27b, which is equal to the distance d. Similarly, the receiving antennas Rx3 and Rx4 have a receiving antenna spacing Drx, that is, the spacing between the phase center line 27c and the phase center line 27d, which is equal to the distance d. The reception antenna spacing Drx is the antenna spacing D1 (see FIG. 12) at the distance d in the first antenna At1. Receiving antennas Rx1 and Rx2 constitute a first antenna group 22a, and receiving antennas Rx3 and Rx4 constitute a first antenna group 22b. The first antenna group distance Dg1s between the first antenna group 22a and the first antenna group 22b, that is, the distance between the phase center line 27a and the phase center line 27c is four times the distance d, that is, 4d. Note that the first antenna group interval Dg1s may be the interval between the phase center line 27b and the phase center line 27d. The first antenna group interval Dg1s is the interval between adjacent first antenna groups.

In the transmitting antennas Tx1 and Tx2, the transmitting antenna spacing Dtx, that is, the spacing between the phase center line 28a and the phase center line 28b is twice the distance d, that is, 2d. The transmission antenna spacing Dtx is an antenna spacing D2 (see FIG. 12) that is twice the distance d at the second antenna At2. The feeding circuit 25 for the transmitting antenna Tx and the receiving antenna Rx is a parallel feeding circuit in which the wiring lengths to each element antenna 19 are equal. Since the transmitting antenna Tx is the second antenna At2 of the second antenna group Gr2, an example is shown in which the feeding circuit 25 is arranged in an area adjacent to other transmitting antennas, and the element antenna 19 is arranged so as not to face each other. Ta. Since the receiving antenna Rx is the first antenna At1 of the first antenna group Gr1, the receiving antennas Rx1 and Rx2 of the first antenna group 22a are connected to the element antenna 19 so that the feeding circuit 25 is not arranged in an area adjacent to other receiving antennas. are arranged to face each other. Similarly, the receiving antennas Rx3 and Rx4 of the first antenna group 22b are arranged so that the element antennas 19 face each other so that the feeding circuit 25 is not arranged in a region adjacent to other receiving antennas.

FIG. 28 shows a virtual reception antenna group 50 formed by the transmission antenna Tx and reception antenna Rx in the antenna arrangement of FIG. 27. The virtual reception antenna group 50 includes a plurality of virtual reception antennas. Eight virtual reception antennas VR1, VR2, VR3, VR4, VR5, VR6, VR7, and VR8 are formed. The virtual receiving antenna spacing Dvr, which is the spacing between adjacent virtual receiving antennas VR among the eight virtual receiving antennas VR, is configured to be equally spaced at a distance d. The virtual receiving antennas VR of the virtual receiving antenna group 50 are arranged at equal distances d in the third arrangement direction dr3. The third arrangement direction dr3 is a direction parallel to the first arrangement direction dr1 and the second arrangement direction dr2.

In the example of FIG. 28, virtual receiving antennas VR1 to VR8 are arranged in the order of VR1, VR2, VR5, VR6, VR3, VR4, VR7, and VR8 toward the positive side in the third arrangement direction dr3. Among these virtual receiving antenna groups 50, VR1, VR2, VR3, and VR4 indicated by solid line circles are virtual receiving antennas formed by signals transmitted by transmitting antenna Tx1 and received by receiving antennas Rx1 to Rx4, and indicated by broken lines VR5, VR6, VR7, and VR8 indicated by circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx2 and received by the receiving antennas Rx1 to Rx4. Virtual reception antennas VR1 and VR2 are virtual reception antennas formed by signals received by reception antennas Rx1 and Rx2 of the first antenna group 22a, and virtual reception antennas VR3 and VR4 are formed by reception antennas Rx3 and Rx4 of the first antenna group 22b. This is a virtual receiving antenna formed by the signals received by the antenna. Therefore, the interval between the virtual reception antenna VR1 formed by the reception antenna Rx1 of the first antenna group 22a and the virtual reception antenna VR3 formed by the reception antenna Rx3 of the first antenna group 22b is the first antenna group interval Dg1s, which is 4d. There is. Virtual receiving antennas VR1 and VR3 are virtual receiving antennas formed by receiving antennas Rx1 and Rx3 on the negative side in the third arrangement direction dr3 in the first antenna sets 22a and 22b. The virtual reception antennas VR2 and VR4 formed by the reception antennas Rx2 and Rx4 on the positive side in the third arrangement direction dr3 in the first antenna groups 22a and 22b are also spaced apart from each other at a first antenna group interval Dg1s of 4d.

Similarly to VR1, VR2, VR3, and VR4 indicated by solid line circles, VR5, VR6, VR7, and VR8 indicated by broken line circles are also virtual receiving antenna VR5 based on receiving antenna Rx1 of first antenna group 22a, and first antenna group 22b. The distance between the receiving antenna Rx3 and the virtual receiving antenna VR7 is the first antenna group distance Dg1s, which is 4d. In other words, the virtual receiving antennas VR5 and VR7 formed by the receiving antennas Rx1 and Rx3 on the negative side in the third arrangement direction dr3 in the first antenna groups 22a and 22b are spaced apart from each other by the first antenna group spacing Dg1s, which is 4d. The virtual reception antennas VR6 and VR8 formed by the reception antennas Rx2 and Rx4 on the positive side in the third arrangement direction dr3 in the first antenna groups 22a and 22b are also spaced apart from each other by the first antenna group spacing Dg1s, which is 4d.

The receiving antenna spacing Drx of the distance d in the first antenna group Gr1, that is, the first antenna group spacing Dg1s between the first antenna groups 22a and 22b having two receiving antennas Rx arranged at the antenna spacing D1 is expressed by equation (3). Decide accordingly.
Dg1s=Ng2×D2...(3)
Here, Ng2 is the number of second antennas, that is, the number of second antennas. In the case of the antenna arrangement in FIG. 27, the number of second antennas Ng2 is 2, the second antenna At2 of the second antenna group Gr2 is the transmitting antenna Tx, and the distance between the adjacent second antennas At2 of the second antenna group Gr2 is The antenna spacing D2 is the transmitting antenna spacing Dtx, which is twice the distance d.

In the case of the antenna arrangement shown in FIG. 27, the first antenna group interval Dg1s is 2×D2, which is 4d. As described above, the plurality of first antennas At1 arranged at antenna intervals D1 of a predetermined distance d may be either the transmitting antenna Tx or the receiving antenna Rx. The second antenna At2 is an antenna that operates in the opposite manner to the first antenna At1. In the antenna arrangement of FIG. 27, there are four first antennas At1 and two second antennas At2. However, the antenna in the radar device 1 of the second embodiment is not limited to this. It is sufficient that the number of first antennas At1 is an even number of four or more, the number of first antenna groups is two or more, and the number of second antennas At2 is two or more.

In the radar device 1 of the second embodiment, the number of first antennas At1 included in the first antenna group Gr1 is an even number of 4 or more, and the number of second antennas At2 included in the second antenna group Gr2 is 2 or more. Yes, the transmitting circuit 12 and the receiving circuit 13 correspond to the number of transmitting antennas Tx, which is one of the first antenna At1 and the second antenna At2, and the number of receiving antennas Rx, which is the other of the first antenna At1 and the second antenna At2. The structure is as follows. In the radar device 1 of the second embodiment, the first antenna group interval Dg1s, which is the adjacent interval in the first antenna group having two first antennas At1 arranged at a predetermined distance d, is The first antenna At1 is arranged so that the value is the product of the number of second antennas Ng2, which is the number of two antennas At2, and the antenna spacing D2, which is the spacing between adjacent second antennas At2 in the second antenna group Gr2. ing. In the radar device 1 of the second embodiment, although the first antenna At1 of three or more channels cannot be physically arranged at intervals of a predetermined distance d, the transmission and reception of the first antenna At1 and the second antenna At2 Since the formed plurality of virtual receiving antennas VR can be arranged at equal intervals of distance d, side lobes can be reduced and false detection can be suppressed.

The radar device 1 of Embodiment 1 including the first antenna At1 and the second antenna At2 arranged in the first to sixth examples of antenna arrangement was suitable when the first antenna At1 had two channels. . On the other hand, the radar device 1 of the second embodiment is suitable when the first antenna At1 has an even number of channels of two or more. Note that in the radar device 1 of the second embodiment, as in the seventh example of the antenna arrangement shown in FIG. may be placed. In this case, the distance, relative velocity, and angle of the target object 33 can be measured two-dimensionally in the third arrangement direction dr3 and the sixth arrangement direction dr6 perpendicular thereto.

Embodiment 3.
FIG. 29 is a diagram showing the antenna arrangement of the radar device according to the third embodiment, and FIG. 30 is a diagram showing the arrangement of the transmitting antenna of FIG. 29. FIG. 31 is a diagram showing a virtual reception antenna group corresponding to the antenna arrangement of FIG. 29. In the radar device 1 of the second embodiment, an example has been described in which the first antenna group Gr1 includes a plurality of two antenna groups in the first arrangement direction dr1. Similarly to the radar device 1 of Embodiment 2, the radar device 1 of the third embodiment is an example in which the first antenna group Gr1 includes a plurality of two antenna groups in the first arrangement direction dr1. This is an example in which the number of second antennas At2 of the second antenna group Gr2 is a prime number of 2 or more. The parts that are different from the radar device 1 of the second embodiment will be mainly explained. The radar apparatus 1 of the third embodiment including antennas having the antenna arrangement shown in FIGS. 29 and 30 has three antenna sets in the first antenna group Gr1, and a second antenna At2 in the second antenna group Gr2. This embodiment differs from the radar device 1 of the second embodiment, which includes antennas having the antenna arrangement shown in FIG. 27, in that the number of antennas Tx is three. Specifically, the radar device 1 according to the third embodiment including the antenna arrangement shown in FIGS. 29 and 30 includes three transmitting antennas Tx1, Tx2, Tx3, six receiving antennas Rx1, Rx2, Rx3, It includes Rx4, Rx5, Rx6, a transmitting circuit 12, a receiving circuit 13, and a processing section 11. The transmitting circuit 12 has a configuration in which a transmitting changeover switch 124 switches between three transmitting antennas Tx1, Tx2, and Tx3. The receiving circuit 13 has a configuration corresponding to six receiving antennas Rx1 to Rx6. The radar device 1 equipped with an antenna having the antenna arrangement shown in FIGS. 29 and 30 transmits a transmission signal having a modulation pattern 61 that repeats in the order of Tx1, Tx2, and Tx3.

The transmitting antenna Tx and receiving antenna Rx will be explained. In the antenna arrangement shown in FIGS. 29 and 30, the receiving antenna Rx is the antenna of the first antenna group Gr1, that is, the first antenna At1, and the transmitting antenna Tx is the antenna of the second antenna group Gr2, that is, the second antenna At2. The receiving antennas Rx1 to Rx6 are arranged in order toward the positive side in the first arrangement direction dr1, and the transmitting antennas Tx1, Tx2, and Tx3 are arranged in order toward the positive side in the second arrangement direction dr2. Receiving antennas Rx1 and Rx2 constitute a first antenna group 22a, receiving antennas Rx3 and Rx4 constitute a first antenna group 22b, and receiving antennas Rx5 and Rx6 constitute a first antenna group 22c. The first antenna set 22a, 22b is as described in the second embodiment. The receiving antennas Rx5 and Rx6 of the first antenna group 22c are arranged such that the receiving antenna spacing Drx, that is, the spacing between the phase center line 27e and the phase center line 27f is equal to the distance d. The reception antenna spacing Drx is the antenna spacing D1 (see FIG. 12) at the distance d in the first antenna At1. The interval between adjacent first antenna sets 22a, 22b, and 22c, that is, the first antenna group interval Dg1s, is six times the distance d, or 6d. The distance between the first antenna group 22a and the first antenna group 22b is the distance between the phase center line 27a and the phase center line 27c or the distance between the phase center line 27b and the phase center line 27d. The distance from one antenna group 22c is the distance between the phase center line 27c and the phase center line 27e or the distance between the phase center line 27d and the phase center line 27f.

Regarding the transmitting antennas Tx1, Tx2, and Tx3, the interval between adjacent transmitting antennas Tx, that is, the transmitting antenna interval Dtx is twice the distance d, that is, 2d. The interval between the transmitting antennas Tx1 and Tx2 is the interval between the phase center line 28a and the phase center line 28b, and the interval between the transmitting antenna Tx2 and the transmitting antenna Tx3 is the interval between the phase center line 28b and the phase center line 28c. be. The transmission antenna spacing Dtx is an antenna spacing D2 (see FIG. 12) that is twice the distance d at the second antenna At2. The feeding circuit 25 for the transmitting antenna Tx and the receiving antenna Rx is a parallel feeding circuit in which the wiring lengths to each element antenna 19 are equal. Since the transmitting antenna Tx is the second antenna At2 of the second antenna group Gr2, an example is shown in which the feeding circuit 25 is arranged in an area adjacent to other transmitting antennas, and the element antenna 19 is arranged so as not to face each other. . Since the receiving antenna Rx is the first antenna At1 of the first antenna group Gr1, the two receiving antennas Rx of the first antenna group 22a, 22b, and 22c are arranged so that the feeding circuit 25 is not placed in an area adjacent to other receiving antennas. , element antennas 19 are arranged to face each other.

FIG. 31 shows a virtual receiving antenna group 50 formed by the transmitting antenna Tx and receiving antenna Rx in the antenna arrangement of FIGS. 29 and 30. The virtual reception antenna group 50 includes a plurality of virtual reception antennas. Eighteen virtual receiving antennas VR1 to VR18 are formed by the three transmitting antennas Tx1 to Tx3, which are the second antennas At2, and the receiving antennas Rx1 to Rx6, which are the six first antennas At1. The virtual reception antenna interval Dvr, which is the interval between adjacent virtual reception antennas VR among the 18 virtual reception antennas VR, is configured to be equally spaced at a distance d. The virtual receiving antennas VR of the virtual receiving antenna group 50 are arranged at equal distances d in the third arrangement direction dr3. The third arrangement direction dr3 is a direction parallel to the first arrangement direction dr1 and the second arrangement direction dr2.

In the example of FIG. 31, virtual receiving antennas VR1 to VR18 are arranged in the order of VR1, VR2, VR7, VR8, VR13, VR14, VR3, VR4, VR9, VR10, VR15, VR16 toward the positive side in the third arrangement direction dr3, respectively. , VR5, VR6, VR11, VR12, VR17, and VR18. Among these virtual receiving antenna groups 50, VR1, VR2, VR3, VR4, VR5, and VR6 indicated by solid white circles are virtual signals formed by signals transmitted by the transmitting antenna Tx1 and received by the receiving antennas Rx1 to Rx6. VR7, VR8, VR9, VR10, VR11, and VR12 indicated by outline broken circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx2 and received by the receiving antennas Rx1 to Rx6. VR13, VR14, VR15, VR16, VR17, and VR18 shown by patterned solid line circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx3 and received by the receiving antennas Rx1 to Rx6.

Virtual reception antennas VR1 and VR2 are virtual reception antennas formed by signals received by reception antennas Rx1 and Rx2 of the first antenna group 22a, and virtual reception antennas VR3 and VR4 are formed by reception antennas Rx3 and Rx4 of the first antenna group 22b. The virtual receiving antennas VR5 and VR6 are virtual receiving antennas formed by the signals received by the receiving antennas Rx5 and Rx6 of the first antenna group 22c. Therefore, the distance between adjacent virtual receiving antennas VR1, VR3, and VR5 by the receiving antenna Rx1 of the first antenna group 22a, the receiving antenna Rx3 of the first antenna group 22b, and the receiving antenna Rx5 of the first antenna group 22c is 6d. The first antenna group interval is Dg1s. The receiving antennas Rx1, Rx3, and Rx5 are receiving antennas Rx on the negative side in the third arrangement direction dr3 in the first antenna groups 22a, 22b, and 22c, but the receiving antennas Rx in the third arrangement direction dr3 in the first antenna groups 22a, 22b, and 22c are The virtual reception antennas VR2, VR4, and VR6 formed by the reception antennas Rx2, Rx4, and Rx6, which are the reception antennas Rx on the positive side, are also spaced apart from each other by the first antenna group spacing Dg1s, which is 6d.

VR7, VR8, VR9, VR10, VR11, and VR12 shown by the white broken line circles also receive reception from the receiving antenna Rx1 of the first antenna group 22a and the first antenna group 22b, similar to VR1 to VR6 shown by the white solid line circles. The spacing between adjacent virtual receiving antennas VR7, VR9, and VR11 by antenna Rx3 and receiving antenna Rx5 of first antenna group 22c is the first antenna group spacing Dg1s, which is 6d. The distance between the virtual receiving antennas VR8, VR10, and VR12 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third array direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 6d. The first antenna group interval is Dg1s.

The patterns VR13, VR14, VR15, VR16, VR17, and VR18 indicated by solid line circles are similar to VR1 to VR6 indicated by white solid line circles, and the reception antenna Rx1 of the first antenna group 22a and the reception antenna Rx1 of the first antenna group 22b are The spacing between adjacent virtual receiving antennas VR13, VR15, and VR17 by antenna Rx3 and receiving antenna Rx5 of first antenna group 22c is the first antenna group spacing Dg1s, which is 6d. The distance between the virtual receiving antennas VR14, VR16, and VR18 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third arrangement direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 6d. The first antenna group interval is Dg1s.

The distance between adjacent first antenna sets 22a, 22b, and 22c having two receiving antennas Rx arranged at a distance d in the first antenna group Gr1, that is, the antenna spacing D1, that is, the distance between adjacent first antenna sets One antenna group interval Dg1s is determined according to equation (3). In the case of the antenna arrangement of FIGS. 29 and 30, the number of second antennas Ng2 is 3, the second antenna At2 of the second antenna group Gr2 is the transmitting antenna Tx, and the adjacent second antenna of the second antenna group Gr2 The antenna interval D2 between At2 is the transmission antenna interval Dtx, which is twice the distance d. In the case of the antenna arrangement shown in FIGS. 29 and 30, the first antenna group interval Dg1s is 3×D2, which is 6d. As described above, the plurality of first antennas At1 arranged at antenna intervals D1 of a predetermined distance d may be either the transmitting antenna Tx or the receiving antenna Rx. The second antenna At2 is an antenna that operates in the opposite manner to the first antenna At1. In the antenna arrangement of FIGS. 29 and 30, there are six first antennas At1 and three second antennas At2. However, the antenna in the radar device 1 of the third embodiment is not limited to this. It is sufficient if the number of first antennas At1 is an even number of four or more, two or more first antenna sets are provided, and the number of second antennas At2 is a prime number of two or more.

In the radar device 1 of the third embodiment, the number of first antennas At1 included in the first antenna group Gr1 is an even number of 4 or more, and the number of second antennas At2 included in the second antenna group Gr2 is 2 or more. The number of transmitting antennas Tx that are prime numbers, and the transmitting circuit 12 and the receiving circuit 13 are one of the first antenna At1 and the second antenna At2, and the number of receiving antennas Rx that is the other of the first antenna At1 and the second antenna At2. It is configured to correspond to In the radar device 1 of the third embodiment, the first antenna group interval Dg1s, which is the adjacent interval in the first antenna group having two first antennas At1 arranged at a predetermined distance d, is The first antenna At1 is arranged so that the value is the product of the number of second antennas Ng2, which is the number of two antennas At2, and the antenna spacing D2, which is the spacing between adjacent second antennas At2 in the second antenna group Gr2. ing. In the radar device 1 of the third embodiment, although the first antenna At1 of three or more channels cannot be physically arranged at intervals of a predetermined distance d, the transmission and reception of the first antenna At1 and the second antenna At2 Since the formed plurality of virtual receiving antennas VR can be arranged at equal intervals of distance d, side lobes can be reduced and false detection can be suppressed.

The radar device 1 of the third embodiment is suitable for the number of first antennas At1 being an even number of two or more channels, and the number of second antennas At2 being a prime number of two or more channels. In the radar device 1 of the third embodiment, even if the second antenna At2 becomes a prime number of 2 or more, the plurality of virtual reception antennas VR formed by the transmission and reception of the first antenna At1 and the second antenna At2 are arranged at equal distances d. Can be placed at intervals. Further, when the second antenna At2 is the transmitting antenna Tx, by arranging the virtual receiving antennas VR together for each transmitting antenna Tx in the set of receiving antennas Rx, that is, the first antenna set 22a, 22b, 22c, multiple virtual The receiving antennas VR can be arranged at equal intervals of distance d. Note that in the radar device 1 of the third embodiment, the antennas of the first antenna group Gr1 and the second antenna group Gr2 are arranged in plural groups in the extending direction of the phase center line, similarly to the seventh example of the antenna arrangement shown in FIG. may be placed. In this case, the distance, relative velocity, and angle of the target object 33 can be measured two-dimensionally in the third arrangement direction dr3 and the sixth arrangement direction dr6 perpendicular thereto.

Embodiment 4.
FIG. 32 is a diagram showing the antenna arrangement of the radar device according to the fourth embodiment, and FIG. 33 is a diagram showing the arrangement of the transmitting antenna of FIG. 32. 34 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 32, FIG. 35 is a diagram showing a first virtual receiving antenna group of FIG. 34, and FIG. 36 is a diagram showing a second virtual receiving antenna group of FIG. 34. It is a figure showing a group. In the radar device 1 of the third embodiment, a method for expanding the antenna arrangement of the radar device 1 of the second embodiment in the case where the number of second antennas At2 of the second antenna group Gr2 is a prime number of 2 or more has been described. The radar device 1 according to the fourth embodiment is an example including a plurality of second antenna groups each including a prime number of second antennas At2 of two or more. The parts that are different from the radar device 1 of Embodiment 3 will be mainly explained. The radar device 1 according to the fourth embodiment including the antennas having the antenna arrangement shown in FIGS. 32 and 33 has two second antenna groups each having three transmitting antennas Tx, which are the second antennas At2, in the second antenna group Gr2. This differs from the radar device 1 of the third embodiment, which includes the antenna arrangement shown in FIGS. 29 and 30. Specifically, the radar device 1 according to the fourth embodiment including antennas having the antenna arrangement shown in FIGS. 32 and 33 has six transmitting antennas Tx1, Tx2, Tx3, Tx4, Tx5, Tx6, and six receiving antennas. It includes Rx1, Rx2, Rx3, Rx4, Rx5, Rx6, a transmitting circuit 12, a receiving circuit 13, and a processing section 11. The transmitting circuit 12 has a configuration in which a transmitting changeover switch 124 switches between six transmitting antennas Tx1 to Tx6. The receiving circuit 13 has a configuration corresponding to six receiving antennas Rx1 to Rx6. The radar device 1 equipped with an antenna having the antenna arrangement shown in FIGS. 32 and 33 transmits a transmission signal having a modulation pattern 61 that repeats in the order of Tx1, Tx2, Tx3, Tx4, Tx5, and Tx6.

The transmitting antenna Tx and receiving antenna Rx will be explained. In the antenna arrangement shown in FIGS. 32 and 33, the receiving antenna Rx is the antenna of the first antenna group Gr1, that is, the first antenna At1, and the transmitting antenna Tx is the antenna of the second antenna group Gr2, that is, the second antenna At2. The receiving antennas Rx1 to Rx6 are arranged in order toward the positive side in the first arrangement direction dr1, and the transmitting antennas Tx1 to Tx6 are arranged in order toward the positive side in the second arrangement direction dr2. Receiving antennas Rx1 and Rx2 constitute a first antenna group 22a, receiving antennas Rx3 and Rx4 constitute a first antenna group 22b, and receiving antennas Rx5 and Rx6 constitute a first antenna group 22c. The first antenna group Gr1 shown in FIG. 32 is the same as the first antenna group Gr1 shown in FIG. 29, so the description will not be repeated.

Transmitting antennas Tx1, Tx2, and Tx3 constitute a second antenna group 24a, and transmitting antennas Tx4, Tx5 , and Tx6 constitute a second antenna group 24b. If the number of second antenna groups, that is, the number of groups is α, and the number of antennas in the second antenna group, that is, the number of antennas in the group is β, then the second antenna group Gr2 in the antenna arrangement shown in FIGS. The number α is 2, the number β of antennas in the group is 3, and six second antennas At2 are provided, which are calculated by α×β. The second antenna set 24a is as described in the third embodiment. The second antenna group 24b also has the same configuration as the second antenna group 24a. Regarding the transmitting antennas Tx4, Tx5, and Tx6, the interval between adjacent transmitting antennas Tx, that is, the transmitting antenna interval Dtx is twice the distance d, that is, 2d. The interval between the transmitting antennas Tx4 and Tx5 is the interval between the phase center line 28d and the phase center line 28e, and the interval between the transmitting antenna Tx5 and the transmitting antenna Tx6 is the interval between the phase center line 28e and the phase center line 28f. be. The transmission antenna spacing Dtx is an antenna spacing D2 (see FIG. 12) that is twice the distance d at the second antenna At2. The feeding circuit 25 for the transmitting antenna Tx and the receiving antenna Rx is a parallel feeding circuit in which the wiring lengths to each element antenna 19 are equal. Since the transmitting antenna Tx is the second antenna At2 of the second antenna group Gr2, an example is shown in which the feeding circuit 25 is arranged in an area adjacent to other transmitting antennas, and the element antenna 19 is arranged so as not to face each other. . Since the receiving antenna Rx is the first antenna At1 of the first antenna group Gr1, the two receiving antennas Rx of the first antenna group 22a, 22b, and 22c are arranged so that the feeding circuit 25 is not placed in an area adjacent to other receiving antennas. , element antennas 19 are arranged to face each other.

A virtual receiving antenna group 50 formed by the transmitting antenna Tx and receiving antenna Rx in the antenna arrangement of FIGS. 32 and 33 is shown in FIGS. 34, 35, and 36. The virtual reception antenna group 50 includes a plurality of virtual reception antennas. Thirty-six virtual receiving antennas VR1 to VR36 are formed by the six transmitting antennas Tx1 to Tx6, which are the second antennas At2, and the receiving antennas Rx1 to Rx6, which are the six first antennas At1. The virtual receiving antenna spacing Dvr, which is the spacing between adjacent virtual receiving antennas VR among the 36 virtual receiving antennas VR, is configured to be equally spaced at a distance d. The virtual receiving antennas VR of the virtual receiving antenna group 50 are arranged at equal distances d in the third arrangement direction dr3. The third arrangement direction dr3 is a direction parallel to the first arrangement direction dr1 and the second arrangement direction dr2.

Since the second antenna group Gr2 includes two second antenna groups 24a and 24b, the virtual receiving antenna group 50 transmits data using the transmitting antenna Tx of the second antenna group 24a and receives the data using the receiving antennas Rx1 to Rx6. A virtual receiving antenna group 51a having virtual receiving antennas VR1 to VR18 formed by signals, and a virtual receiving antenna VR19 formed by signals transmitted by the transmitting antenna Tx of the second antenna group 24b and received by the receiving antennas Rx1 to Rx6. - virtual receiving antenna group 51b having VR36. The virtual receiving antenna group 51a shown in FIG. 35 has the same configuration as the virtual receiving antenna group 50 shown in FIG. 31 described in the third embodiment.

The virtual receiving antenna group 51b has the same configuration as the virtual receiving antenna group 51a. In the example of FIG. 36, virtual receiving antennas VR19 to VR36 are arranged in the order of VR19, VR20, VR25, VR26, VR31, VR32, VR21, VR22, VR27, VR28, VR33, VR34 toward the positive side in the third arrangement direction dr3, respectively. , VR23, VR24, VR29, VR30, VR35, and VR36 are arranged in this order. Of this virtual receiving antenna group 51b, VR19, VR20, VR21, VR22, VR23, and VR24 indicated by solid white circles are virtual reception formed by signals transmitted by the transmitting antenna Tx4 and received by the receiving antennas Rx1 to Rx6. The antennas VR25, VR26, VR27, VR28, VR29, and VR30 indicated by white dashed circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx5 and received by the receiving antennas Rx1 to Rx6. VR31, VR32, VR33, VR34, VR35, and VR36 shown by patterned solid line circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx6 and received by the receiving antennas Rx1 to Rx6.

Virtual reception antennas VR19 and VR20 are virtual reception antennas formed by signals received by reception antennas Rx1 and Rx2 of the first antenna group 22a, and virtual reception antennas VR21 and VR22 are formed by reception antennas Rx3 and Rx4 of the first antenna group 22b. The virtual receiving antennas VR23 and VR24 are virtual receiving antennas formed by the signals received by the receiving antennas Rx5 and Rx6 of the first antenna group 22c. Therefore, the distance between adjacent virtual receiving antennas VR19, VR21, and VR23 by receiving antenna Rx1 of first antenna group 22a, receiving antenna Rx3 of first antenna group 22b, and receiving antenna Rx5 of first antenna group 22c is 6d. The first antenna group interval is Dg1s. The receiving antennas Rx1, Rx3, and Rx5 are receiving antennas Rx on the negative side in the third arrangement direction dr3 in the first antenna groups 22a, 22b, and 22c, but the receiving antennas Rx in the third arrangement direction dr3 in the first antenna groups 22a, 22b, and 22c are The virtual reception antennas VR20, VR22, and VR24 formed by the reception antennas Rx2, Rx4, and Rx6, which are the reception antennas Rx on the positive side, are also spaced apart from each other by the first antenna group spacing Dg1s, which is 6d.

VR25, VR26, VR27, VR28, VR29, and VR30 shown by the white broken line circles also receive reception from the receiving antenna Rx1 of the first antenna group 22a and the first antenna group 22b, similar to VR19 to VR24 shown by the white solid line circles. The distance between adjacent virtual receiving antennas VR25, VR27, and VR29 by the antenna Rx3 and the receiving antenna Rx5 of the first antenna group 22c is the first antenna group distance Dg1s, which is 6d. The distance between the virtual receiving antennas VR26, VR28, and VR30 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third array direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 6d. The first antenna group interval is Dg1s.

Patterns VR31, VR32, VR33, VR34, VR35, and VR36 indicated by solid line circles are similar to VR19 to VR24 indicated by white solid line circles, and receive antenna Rx1 of the first antenna group 22a and reception of the first antenna group 22b. The distance between adjacent virtual receiving antennas VR31, VR33, and VR35 by the antenna Rx3 and the receiving antenna Rx5 of the first antenna group 22c is the first antenna group distance Dg1s, which is 6d. The distance between the virtual receiving antennas VR32, VR34, and VR36 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third arrangement direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 6d. The first antenna group interval is Dg1s.

The distance between adjacent first antenna sets 22a, 22b, 22c having two receiving antennas Rx arranged at a distance d, that is, the antenna spacing D1, in the first antenna group Gr1 is One antenna group interval Dg1s is determined according to equation (4).
Dg1s=β×D2...(4)
As described above, β is the number of antennas in the second antenna group, that is, the number of antennas in the group. In the case of the antenna arrangement shown in FIGS. 32 and 33, the number β of antennas in the second antenna group is 3, the second antenna At2 of the second antenna group Gr2 is the transmitting antenna Tx, and the second antenna group Gr2 is the transmitting antenna Tx. The antenna spacing D2 between adjacent second antennas At2 in each of the second antenna sets 24a, 24b is a transmitting antenna spacing Dtx that is twice the distance d. In the case of the antenna arrangement shown in FIGS. 32 and 33, the first antenna group interval Dg1s is 3×D2, which is 6d.

The second antenna group spacing Dg2s between the second antenna groups 24a and 24b having three transmitting antennas Tx arranged at the antenna spacing D2, that is, the transmitting antenna spacing Dtx that is twice the distance d in the second antenna group Gr2, is expressed by the formula (5). The second antenna group interval Dg2s is the interval between adjacent second antenna groups.
Dg2s=Dg1s×Ng1/2 (5)
Here, Ng1 is the number of first antennas, that is, the number of first antennas. In the case of the antenna arrangement shown in FIGS. 32 and 33, the first antenna group interval Dg1s is 6d, and the first number Ng1 of antennas is 6.

In the case of the antenna arrangement shown in FIGS. 32 and 33, the second antenna group interval Dg2s is 18d, which is calculated by 6d×6/2. As described above, the plurality of first antennas At1 arranged at antenna intervals D1 of a predetermined distance d may be either the transmitting antenna Tx or the receiving antenna Rx. The second antenna At2 is an antenna that operates in the opposite manner to the first antenna At1. In the antenna arrangement of FIGS. 32 and 33, there are six first antennas At1 and six second antennas At2. However, the antenna in radar device 1 of Embodiment 4 is not limited to this. It is sufficient that the number of first antennas At1, that is, the number of first antennas Ng1, is an even number of 4 or more, that two or more first antenna groups are provided, and that the number of second antennas At2, that is, the number of second antennas Ng2 is α × β. . Here, the number α of second antenna groups in the second antenna group Gr2 and the number β of antennas in the group are both integers of 2 or more.

In the radar device 1 of the fourth embodiment, the number of first antennas At1 included in the first antenna group Gr1 is an even number of 4 or more, and the number of second antennas At2 included in the second antenna group Gr2 is α×β. , the transmitting circuit 12 and the receiving circuit 13 correspond to the number of transmitting antennas Tx, which is one of the first antenna At1 and the second antenna At2, and the number of receiving antennas Rx, which is the other of the first antenna At1 and the second antenna At2. It has a corresponding configuration. In the radar device 1 of the fourth embodiment, the first antenna group interval Dg1s, which is the adjacent interval in the first antenna group having two first antennas At1 arranged at a predetermined distance d, is It is the value obtained by multiplying the number of antennas in the group β, which is the number of second antennas At2 in the two antenna groups 24a and 24b, by the antenna spacing D2, which is the spacing between adjacent second antennas At2 in the second antenna groups 24a and 24b. The first antenna At1 is arranged as follows. In addition, the radar device 1 of the fourth embodiment has second antennas At2 of β antennas arranged at an antenna spacing D2, and the adjoining spacing between α second antenna sets 24a and 24b. The second antenna At2 is arranged so that the second antenna group interval Dg2s is a value obtained by dividing the product of the first antenna group interval Dg1s and the first number Ng1, which is the number of first antennas At1, by 2. . In the radar device 1 of the fourth embodiment, although the first antenna At1 of three or more channels cannot be physically arranged at intervals of a predetermined distance d, the transmission and reception of the first antenna At1 and the second antenna At2 Since the formed plurality of virtual receiving antennas VR can be arranged at equal intervals of distance d, side lobes can be reduced and false detection can be suppressed.

In the radar device 1 of the fourth embodiment, the number of first antennas At1 is an even number of 2 or more channels, and the number of second antennas At2 is α×β, which is the product of the number of sets α and the number of antennas in the set β. Suitable for cases where The radar device 1 of the fourth embodiment can be configured by transmitting and receiving the first antenna At1 and the second antenna At2 even when the first antenna At1 having three or more channels cannot be physically arranged at intervals of a predetermined distance d. A plurality of virtual receiving antennas VR can be arranged at equal intervals with a distance d. Further, when the second antenna At2 is the transmitting antenna Tx, by arranging the virtual receiving antennas VR together for each transmitting antenna Tx in the set of receiving antennas Rx, that is, the first antenna set 22a, 22b, 22c, multiple virtual The receiving antennas VR can be arranged at equal intervals of distance d. Note that in the radar device 1 of the fourth embodiment, the antennas of the first antenna group Gr1 and the second antenna group Gr2 are arranged in plural groups in the extending direction of the phase center line, similarly to the seventh example of the antenna arrangement shown in FIG. may be placed. In this case, the distance, relative velocity, and angle of the target object 33 can be measured two-dimensionally in the third arrangement direction dr3 and the sixth arrangement direction dr6 perpendicular thereto.

In the antenna arrangement examples of FIGS. 32 and 33, the first antenna group Gr1 and the second antenna group Gr2 are arranged side by side in different antenna arrangement directions, that is, the second antenna group Gr2 is arranged in the second arrangement direction dr2. An example is shown in which the first antenna group Gr1 is arranged on the positive side of the antenna. However, the first antenna group Gr1 and the second antenna group Gr2 may be arranged side by side in the extending direction of the phase center line of each antenna as shown in FIG. 37. In the antenna arrangement example of FIG. 37, the first antenna group Gr1 is arranged above the second antenna group Gr2 in the drawing. When the first antenna group Gr1 and the second antenna group Gr2 are arranged side by side in the extending direction of the phase center line of each antenna, the virtual receiving antennas VR are arranged at equal intervals of a predetermined distance d. The longitudinal lengths of the transmitting antenna Tx and receiving antenna Rx of the radar device 1, that is, the lengths in the first arrangement direction dr1 and the second arrangement direction dr2 can be reduced. In this case, even if the total number of transmitting antennas Tx and receiving antennas Rx increases, the lengths in the longitudinal direction of the transmitting antennas Tx and receiving antennas Rx, that is, the lengths in the longitudinal direction of the antennas are This can prevent the portion 11 from protruding longer than the length of the antenna in the longitudinal direction. When the total number of transmitting antennas Tx and receiving antennas Rx on the same straight line increases, the length of the radar device 1 in the longitudinal direction increases in accordance with the length of the antennas in the longitudinal direction. Therefore, when the total number of transmitting antennas Tx and receiving antennas Rx increases, the lengths of the transmitting antennas Tx and receiving antennas Rx in the longitudinal direction of the antennas are shortened, thereby shortening the length of the radar device 1 in the longitudinal direction. be able to.

Embodiment 5.
37 is a diagram showing the antenna arrangement of the radar device according to the fifth embodiment, FIG. 38 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 37, and FIG. 39 is a diagram showing the third antenna arrangement of FIG. 37. FIG. 3 is a diagram showing a virtual reception antenna group. The radar device 1 according to the fifth embodiment is an example in which the number α of second antenna groups in the second antenna group Gr2 in the radar device 1 according to the fourth embodiment is three. The differences from the radar device 1 of Embodiment 4 will mainly be explained. The radar device 1 according to the fifth embodiment, which includes antennas having the antenna arrangement shown in FIG. 37, includes three second antenna groups having three transmitting antennas Tx, which are the second antennas At2, in the second antenna group Gr2. This is different from the radar device 1 of the fourth embodiment, which includes the antenna arrangement shown in FIGS. 32 and 33. When expressed using the number α of second antennas At2 in the second antenna group Gr2 and the number β of antennas in the group, the radar apparatus 1 of the fourth embodiment equipped with antennas having the antenna arrangement shown in FIGS. This is an example in which the number α and the number β of antennas in a group are 2 and 3, respectively, and the radar apparatus 1 of Embodiment 5 equipped with antennas having the antenna arrangement shown in FIG. and 3 are examples.

Specifically, the radar device 1 according to the fifth embodiment including the antennas having the antenna arrangement shown in FIG. receiving antennas Rx1, Rx2, Rx3, Rx4, Rx5, Rx6, a transmitting circuit 12, a receiving circuit 13, and a processing section 11. The transmitting circuit 12 has a configuration in which a transmitting changeover switch 124 switches between nine transmitting antennas Tx1 to Tx9. The receiving circuit 13 has a configuration corresponding to six receiving antennas Rx1 to Rx6. The radar device 1 equipped with an antenna having the antenna arrangement shown in FIG. 37 transmits a transmission signal having a modulation pattern 61 that repeats in the order of Tx1, Tx2, Tx3, Tx4, Tx5, Tx6, Tx7, Tx8, and Tx9.

The transmitting antenna Tx and receiving antenna Rx will be explained. In the antenna arrangement shown in FIG. 37, the receiving antenna Rx is the antenna of the first antenna group Gr1, that is, the first antenna At1, and the transmitting antenna Tx is the antenna of the second antenna group Gr2, that is, the second antenna At2. The receiving antennas Rx1 to Rx6 are arranged in order toward the positive side in the first arrangement direction dr1, and the transmitting antennas Tx1 to Tx9 are arranged in order toward the positive side in the second arrangement direction dr2. Receiving antennas Rx1 and Rx2 constitute a first antenna group 22a, receiving antennas Rx3 and Rx4 constitute a first antenna group 22b, and receiving antennas Rx5 and Rx6 constitute a first antenna group 22c. The first antenna group Gr1 shown in FIG. 37 is the same as the first antenna group Gr1 shown in FIG. 32, so the description will not be repeated.

Transmitting antennas Tx1, Tx2, and Tx3 constitute a second antenna group 24a, transmitting antennas Tx4, Tx5, and Tx6 constitute a second antenna group 24b, and transmitting antennas Tx7, Tx8, and Tx9 constitute a second antenna group 24c. . When expressed using the number α of second antennas At2 in the second antenna group Gr2 and the number β of antennas in the group, the second antenna group Gr2 in the antenna arrangement shown in FIG. The number β is 3, and nine second antennas At2 are provided, which is calculated by α×β. The second antenna set 24a, 24b is as described in the fourth embodiment. The second antenna group 24c also has the same configuration as the second antenna groups 24a and 24b. Regarding the transmitting antennas Tx7, Tx8, and Tx9, the interval between adjacent transmitting antennas Tx, that is, the transmitting antenna interval Dtx is twice the distance d, that is, 2d. The interval between the transmitting antennas Tx7 and Tx8 is the interval between the phase center line 28g and the phase center line 28h, and the interval between the transmitting antenna Tx8 and the transmitting antenna Tx9 is the interval between the phase center line 28h and the phase center line 28i. be. The transmission antenna spacing Dtx is an antenna spacing D2 (see FIG. 12) that is twice the distance d at the second antenna At2. The feeding circuit 25 for the transmitting antenna Tx and the receiving antenna Rx is the same as that in the radar device 1 of the fourth embodiment, and is a parallel feeding circuit in which the wiring lengths to each element antenna 19 are equal. Ta.

FIG. 38 shows a virtual receiving antenna group 50 formed by the transmitting antenna Tx and receiving antenna Rx in the antenna arrangement of FIG. 37. The virtual receiving antenna group 50 shown in FIG. 38 is composed of virtual receiving antenna groups 51a, 51b, and 51c. The virtual receiving antenna groups 51a and 51b are the same as the virtual receiving antenna groups 51a and 51b shown in FIGS. 35 and 36, respectively, and the virtual receiving antenna group 51c is shown in FIG. 39. 54 virtual receiving antennas VR1 to VR54 are formed by the nine transmitting antennas Tx1 to Tx9, which are the second antennas At2, and the receiving antennas Rx1 to Rx6, which are the six first antennas At1. The virtual reception antenna interval Dvr, which is the interval between adjacent virtual reception antennas VR among the 54 virtual reception antennas VR, is configured to be equally spaced at a distance d. The virtual receiving antennas VR of the virtual receiving antenna group 50 are arranged at equal distances d in the third arrangement direction dr3. The third arrangement direction dr3 is a direction parallel to the first arrangement direction dr1 and the second arrangement direction dr2.

Since the second antenna group Gr2 includes three second antenna groups 24a, 24b, and 24c, the virtual receiving antenna group 50 transmits using the transmitting antenna Tx of the second antenna group 24a and using the receiving antennas Rx1 to Rx6. A virtual reception antenna group 51a having virtual reception antennas VR1 to VR18 formed by received signals and a virtual reception formed by signals transmitted by the transmission antenna Tx of the second antenna group 24b and received by reception antennas Rx1 to Rx6. A virtual receiving antenna group 51b having antennas VR19 to VR36, and virtual receiving antennas VR37 to VR54 formed by signals transmitted by the transmitting antenna Tx of the second antenna group 24c and received by receiving antennas Rx1 to Rx6. The group 51c is composed of a group 51c.

The virtual receiving antenna group 51c has the same configuration as the virtual receiving antenna groups 51a and 51b. In the example of FIG. 39, the virtual receiving antennas VR37 to VR54 are arranged as follows: VR37, VR38, VR43, VR44, VR49, VR50, VR39, VR40, VR45, VR46, VR51, VR52, respectively, toward the positive side in the third arrangement direction dr3. , VR41, VR42, VR47, VR48, VR53, and VR54. Of this virtual receiving antenna group 51c, VR37, VR38, VR39, VR40, VR41, and VR42 indicated by solid white circles are virtual reception formed by signals transmitted by the transmitting antenna Tx7 and received by the receiving antennas Rx1 to Rx6. The antennas VR43, VR44, VR45, VR46, VR47, and VR48 indicated by white dashed circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx8 and received by the receiving antennas Rx1 to Rx6. VR49, VR50, VR51, VR52, VR53, and VR54 shown by patterned solid line circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx9 and received by the receiving antennas Rx1 to Rx6.

Virtual reception antennas VR37 and VR38 are virtual reception antennas formed by signals received by reception antennas Rx1 and Rx2 of the first antenna group 22a, and virtual reception antennas VR39 and VR40 are formed by reception antennas Rx3 and Rx4 of the first antenna group 22b. The virtual receiving antennas VR41 and VR42 are virtual receiving antennas formed by the signals received by the receiving antennas Rx5 and Rx6 of the first antenna group 22c. Therefore, the distance between adjacent virtual receiving antennas VR37, VR39, and VR41 by receiving antenna Rx1 of first antenna group 22a, receiving antenna Rx3 of first antenna group 22b, and receiving antenna Rx5 of first antenna group 22c is 6d. The first antenna group interval is Dg1s. The receiving antennas Rx1, Rx3, and Rx5 are receiving antennas Rx on the negative side in the third arrangement direction dr3 in the first antenna groups 22a, 22b, and 22c, but the receiving antennas Rx in the third arrangement direction dr3 in the first antenna groups 22a, 22b, and 22c are The virtual reception antennas VR38, VR40, and VR42 formed by the reception antennas Rx2, Rx4, and Rx6, which are the reception antennas Rx on the positive side, are also spaced apart from each other by the first antenna group spacing Dg1s, which is 6d.

VR43, VR44, VR45, VR46, VR47, and VR48 shown by the white broken line circles also receive the reception antenna Rx1 of the first antenna group 22a and the first antenna group 22b in the same way as VR37 to VR42 shown by the white solid line circles. The spacing between adjacent virtual receiving antennas VR43, VR45, and VR47 by antenna Rx3 and receiving antenna Rx5 of first antenna group 22c is the first antenna group spacing Dg1s, which is 6d. The distance between the virtual receiving antennas VR44, VR46, and VR48 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third arrangement direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 6d. The first antenna group interval is Dg1s.

Patterns VR49, VR50, VR51, VR52, VR53, and VR54 indicated by solid line circles are similar to VR37 to VR42 indicated by white solid line circles, and receive antenna Rx1 of the first antenna group 22a and reception of the first antenna group 22b. The spacing between adjacent virtual receiving antennas VR49, VR51, and VR53 by antenna Rx3 and receiving antenna Rx5 of first antenna group 22c is the first antenna group spacing Dg1s, which is 6d. The distance between the virtual receiving antennas VR50, VR52, and VR54 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third array direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 6d. The first antenna group interval is Dg1s.

The distance between adjacent first antenna sets 22a, 22b, and 22c having two receiving antennas Rx arranged at a distance d in the first antenna group Gr1, that is, the antenna spacing D1, that is, the distance between adjacent first antenna sets One antenna group interval Dg1s is determined according to equation (4). A second antenna group spacing Dg2s between the second antenna groups 24a, 24b, and 24c having three transmitting antennas Tx arranged at an antenna spacing D2, that is, a transmitting antenna spacing Dtx that is twice the distance d in the second antenna group Gr2. , determined according to equation (5).

In the case of the antenna arrangement in FIG. 37, the number β of antennas in the second antenna group is 3, the second antenna At2 of the second antenna group Gr2 is the transmitting antenna Tx, and each antenna of the second antenna group Gr2 is The antenna interval D2 between adjacent second antennas At2 in the two antenna sets 24a, 24b, and 24c is the transmission antenna interval Dtx, which is twice the distance d. In the case of the antenna arrangement of FIG. 37, the first antenna group interval Dg1s is 3×D2, which is 6d, as in the case of the antenna arrangement of FIGS. 32 and 33. Since the first antenna group interval Dg1s is 6d and the first number of antennas Ng1 is 6, the second antenna group spacing Dg2s is calculated as 6d x 6/2, as in the case of the antenna arrangement in FIGS. 32 and 33. It becomes 18d.

As described above, the plurality of first antennas At1 arranged at antenna intervals D1 of a predetermined distance d may be either the transmitting antenna Tx or the receiving antenna Rx. The second antenna At2 is an antenna that operates in the opposite manner to the first antenna At1. In the antenna arrangement of FIG. 37, there are six first antennas At1 and nine second antennas At2. However, the antenna in the radar device 1 of the fifth embodiment is not limited to this as described in the fourth embodiment. It is sufficient that the number of first antennas At1, that is, the number of first antennas Ng1, is an even number of 4 or more, that two or more first antenna groups are provided, and that the number of second antennas At2, that is, the number of second antennas Ng2 is α × β. .

In the radar device 1 of the fifth embodiment, the number of first antennas At1 included in the first antenna group Gr1 is an even number of 4 or more, and the number of second antennas At2 included in the second antenna group Gr2 is α×β. , the transmitting circuit 12 and the receiving circuit 13 correspond to the number of transmitting antennas Tx, which is one of the first antenna At1 and the second antenna At2, and the number of receiving antennas Rx, which is the other of the first antenna At1 and the second antenna At2. It has a corresponding configuration. In the radar device 1 of the fifth embodiment, the first antenna group interval Dg1s, which is the adjacent interval in the first antenna group having two first antennas At1 arranged at a predetermined distance d, is Multiply the number of antennas in the group β, which is the number of second antennas At2 in the two antenna groups 24a, 24b, and 24c, by the antenna spacing D2, which is the spacing between adjacent second antennas At2 in the second antenna groups 24a, 24b, and 24c. The first antenna At1 is arranged so as to have a value of . Further, the radar device 1 of the fifth embodiment has second antennas At2 of β antennas arranged at an antenna spacing D2, and the adjacent antenna groups 24a, 24b, 24c have α second antenna groups 24a, 24b, and 24c. The second antenna At2 is arranged so that the second antenna group interval Dg2s is equal to the product of the first antenna group interval Dg1s and the first number Ng1, which is the number of first antennas At1, divided by 2. ing. In the radar device 1 of the fifth embodiment, although the first antenna At1 of three or more channels cannot be physically arranged at intervals of a predetermined distance d, the transmission and reception of the first antenna At1 and the second antenna At2 Since the formed plurality of virtual receiving antennas VR can be arranged at equal intervals of distance d, side lobes can be reduced and false detection can be suppressed.

The radar device 1 of Embodiment 5 is a case where the number α of the second antenna groups of the second antenna group Gr2 in the radar device 1 of Embodiment 4 is 3, and the radar device 1 of Embodiment 4 is different from the radar device 1 of Embodiment 4. It has a similar effect.

Embodiment 6.
FIG. 40 is a diagram showing the antenna arrangement of the radar device according to the sixth embodiment, and FIG. 41 is a diagram showing a virtual receiving antenna group corresponding to the antenna arrangement of FIG. 40. 42, FIG. 43, and FIG. 44 are diagrams showing the first virtual receiving antenna group in FIG. 41, the second virtual receiving antenna group in FIG. 41, and the third virtual receiving antenna group in FIG. 41, respectively. The radar device 1 according to the sixth embodiment is an example in which the number β of antennas in the second antenna group in the second antenna group Gr2 in the radar device 1 according to the fifth embodiment is two. The parts that are different from the radar device 1 of Embodiment 5 will be mainly explained. The radar device 1 according to the sixth embodiment including the antenna arrangement shown in FIG. 40 includes three second antenna groups each having two transmitting antennas Tx, which are the second antennas At2, in the second antenna group Gr2. This is different from the radar apparatus 1 of the fifth embodiment, which includes an antenna having the antenna arrangement shown in FIG. When expressed using the number α of second antennas At2 in the second antenna group Gr2 and the number β of antennas in the group, the radar apparatus 1 of the fifth embodiment including the antennas having the antenna arrangement shown in FIG. This is an example in which the number of antennas in a group β is 3 and 3, respectively, and the radar apparatus 1 of the sixth embodiment including the antenna with the antenna arrangement shown in FIG. This is an example.

Specifically, the radar device 1 according to the sixth embodiment including antennas having the antenna arrangement shown in FIG. , Rx3, Rx4, Rx5, Rx6, a transmitting circuit 12, a receiving circuit 13, and a processing section 11. The transmitting circuit 12 is configured such that a transmitting changeover switch 124 switches between six transmitting antennas Tx1 to Tx6. The receiving circuit 13 has a configuration corresponding to six receiving antennas Rx1 to Rx6. The radar device 1 equipped with an antenna having the antenna arrangement shown in FIG. 40 transmits a transmission signal having a modulation pattern 61 that repeats in the order of Tx1, Tx2, Tx3, Tx4, Tx5, and Tx6.

The transmitting antenna Tx and receiving antenna Rx will be explained. In the antenna arrangement shown in FIG. 40, the receiving antenna Rx is the antenna of the first antenna group Gr1, that is, the first antenna At1, and the transmitting antenna Tx is the antenna of the second antenna group Gr2, that is, the second antenna At2. The receiving antennas Rx1 to Rx6 are arranged in order toward the positive side in the first arrangement direction dr1, and the transmitting antennas Tx1 to Tx6 are arranged in order toward the positive side in the second arrangement direction dr2. Receiving antennas Rx1 and Rx2 constitute a first antenna group 22a, receiving antennas Rx3 and Rx4 constitute a first antenna group 22b, and receiving antennas Rx5 and Rx6 constitute a first antenna group 22c. The first antenna group Gr1 shown in FIG. 40 is the same as the first antenna group Gr1 shown in FIG. 37, so the description will not be repeated.

Transmitting antennas Tx1 and Tx2 constitute a second antenna group 24a, transmitting antennas Tx3 and Tx4 constitute a second antenna group 24b, and transmitting antennas Tx5 and Tx6 constitute a second antenna group 24c. When expressed using the number α of second antennas At2 in the second antenna group Gr2 and the number β of antennas in the group, the second antenna group Gr2 in the antenna arrangement shown in FIG. The number β is 2, and six second antennas At2 are provided, which is calculated by α×β. Regarding the transmitting antennas Tx1 and Tx2 in the second antenna group 24a, the interval between adjacent transmitting antennas Tx, that is, the transmitting antenna interval Dtx is twice the distance d, that is, 2d. The distance between the transmitting antenna Tx1 and the transmitting antenna Tx2 is the distance between the phase center line 28a and the phase center line 28b. The transmission antenna spacing Dtx is an antenna spacing D2 (see FIG. 12) that is twice the distance d at the second antenna At2. The second antenna sets 24b and 24c also have the same configuration as the second antenna set 24a. In the transmitting antennas Tx3 and Tx4 in the second antenna group 24b, the interval between adjacent transmitting antennas Tx, that is, the transmitting antenna interval Dtx is twice the distance d, that is, 2d. The distance between the transmitting antenna Tx3 and the transmitting antenna Tx4 is the distance between the phase center line 28c and the phase center line 28d. In the transmitting antennas Tx5 and Tx6 in the second antenna group 24c, the interval between adjacent transmitting antennas Tx, that is, the transmitting antenna interval Dtx is twice the distance d, that is, 2d. The distance between the transmitting antenna Tx5 and the transmitting antenna Tx6 is the distance between the phase center line 28e and the phase center line 28f.

The feeding circuit 25 for the transmitting antenna Tx and the receiving antenna Rx is a parallel feeding circuit in which the wiring lengths to each element antenna 19 are equal. The transmitting antenna Tx is the second antenna At2 of the second antenna group Gr2, but the element antennas 19 of the two transmitting antennas Tx face each other so that the feeding circuit 25 is not placed in an area adjacent to other transmitting antennas. An example of the layout is shown below. Since the receiving antenna Rx is the first antenna At1 of the first antenna group Gr1, the two receiving antennas Rx of the first antenna group 22a, 22b, and 22c are arranged so that the feeding circuit 25 is not placed in an area adjacent to other receiving antennas. , element antennas 19 are arranged to face each other.

A virtual receiving antenna group 50 formed by the transmitting antenna Tx and receiving antenna Rx in the antenna arrangement of FIG. 40 is shown in FIGS. 41, 42, 43, and 44. The virtual reception antenna group 50 includes a plurality of virtual reception antennas. Thirty-six virtual receiving antennas VR1 to VR36 are formed by the six transmitting antennas Tx1 to Tx6, which are the second antennas At2, and the receiving antennas Rx1 to Rx6, which are the six first antennas At1. The virtual receiving antenna spacing Dvr, which is the spacing between adjacent virtual receiving antennas VR among the 36 virtual receiving antennas VR, is configured to be equally spaced at a distance d. The virtual receiving antennas VR of the virtual receiving antenna group 50 are arranged at equal distances d in the third arrangement direction dr3. The third arrangement direction dr3 is a direction parallel to the first arrangement direction dr1 and the second arrangement direction dr2.

Since the second antenna group Gr2 includes three second antenna groups 24a, 24b, and 24c, the virtual receiving antenna group 50 transmits using the transmitting antenna Tx of the second antenna group 24a and using the receiving antennas Rx1 to Rx6. Virtual receiving antenna group 52a having virtual receiving antennas VR1 to VR12 formed by received signals, and virtual reception formed by signals transmitted by transmitting antennas Tx of second antenna group 24b and received by receiving antennas Rx1 to Rx6. A virtual receiving antenna group 52b having antennas VR13 to VR24 and virtual receiving antennas VR25 to VR36 formed by signals transmitted by the transmitting antenna Tx of the second antenna group 24c and received by receiving antennas Rx1 to Rx6. and a group 52c.

In the example of the virtual reception antenna group 52a shown in FIG. 42, the virtual reception antennas VR1 to VR12 are arranged in the order of VR1, VR2, VR7, VR8, VR3, VR4, VR9, VR10 toward the positive side in the third arrangement direction dr3, respectively. , VR5, VR6, VR11, and VR12. Of this virtual receiving antenna group 52a, VR1, VR2, VR3, VR4, VR5, and VR6 indicated by solid white circles are virtual reception formed by signals transmitted by the transmitting antenna Tx1 and received by the receiving antennas Rx1 to Rx6. The antennas VR7, VR8, VR9, VR10, VR11, and VR12 indicated by white dashed circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx2 and received by the receiving antennas Rx1 to Rx6.

Virtual reception antennas VR1 and VR2 are virtual reception antennas formed by signals received by reception antennas Rx1 and Rx2 of the first antenna group 22a, and virtual reception antennas VR3 and VR4 are formed by reception antennas Rx3 and Rx4 of the first antenna group 22b. The virtual receiving antennas VR5 and VR6 are virtual receiving antennas formed by the signals received by the receiving antennas Rx5 and Rx6 of the first antenna group 22c. Therefore, the distance between adjacent virtual receiving antennas VR1, VR3, and VR5 by the receiving antenna Rx1 of the first antenna group 22a, the receiving antenna Rx3 of the first antenna group 22b, and the receiving antenna Rx5 of the first antenna group 22c is 4d. The first antenna group interval is Dg1s. The receiving antennas Rx1, Rx3, and Rx5 are receiving antennas Rx on the negative side in the third arrangement direction dr3 in the first antenna groups 22a, 22b, and 22c, but the receiving antennas Rx in the third arrangement direction dr3 in the first antenna groups 22a, 22b, and 22c are The virtual reception antennas VR2, VR4, and VR6 formed by the reception antennas Rx2, Rx4, and Rx6, which are the reception antennas Rx on the positive side, are also spaced apart from each other by the first antenna group spacing Dg1s, which is 4d.

VR7, VR8, VR9, VR10, VR11, and VR12 shown by the white broken line circles are similar to VR1 to VR6 shown by the white solid line circles, and the reception antenna Rx1 of the first antenna group 22a and the reception antenna Rx1 of the first antenna group 22b are The spacing between adjacent virtual receiving antennas VR7, VR9, and VR11 by antenna Rx3 and receiving antenna Rx5 of first antenna group 22c is the first antenna group spacing Dg1s, which is 4d. The distance between the virtual receiving antennas VR8, VR10, and VR12 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third arrangement direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 4d. The first antenna group interval is Dg1s.

The virtual receiving antenna group 52b has the same configuration as the virtual receiving antenna group 52a. In the example of FIG. 43, virtual receiving antennas VR13 to VR24 are arranged in the order of VR13, VR14, VR19, VR20, VR15, VR16, VR21, VR22, VR17, VR18, VR23, VR24 toward the positive side in the third arrangement direction dr3, respectively. They are arranged in this order. Of this virtual receiving antenna group 52b, VR13, VR14, VR15, VR16, VR17, and VR18 indicated by solid white circles are virtual reception formed by signals transmitted by the transmitting antenna Tx3 and received by the receiving antennas Rx1 to Rx6. The antennas VR19, VR20, VR21, VR22, VR23, and VR24 indicated by white dashed circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx4 and received by the receiving antennas Rx1 to Rx6.

Virtual reception antennas VR13 and VR14 are virtual reception antennas formed by signals received by reception antennas Rx1 and Rx2 of the first antenna group 22a, and virtual reception antennas VR15 and VR16 are formed by reception antennas Rx3 and Rx4 of the first antenna group 22b. The virtual receiving antennas VR17 and VR18 are virtual receiving antennas formed by the signals received by the receiving antennas Rx5 and Rx6 of the first antenna group 22c. Therefore, the distance between the adjacent virtual receiving antennas VR13, VR15, and VR17 by the receiving antenna Rx1 of the first antenna group 22a, the receiving antenna Rx3 of the first antenna group 22b, and the receiving antenna Rx5 of the first antenna group 22c is 4d. The first antenna group interval is Dg1s. The distance between the virtual receiving antennas VR14, VR16, and VR18 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third arrangement direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 4d. The first antenna group interval is Dg1s.

VR19, VR20, VR21, VR22, VR23, and VR24 shown by the white broken line circles also receive reception from the receiving antenna Rx1 of the first antenna group 22a and the first antenna group 22b, similar to VR13 to VR18 shown by the white solid line circles. The spacing between adjacent virtual receiving antennas VR19, VR21, and VR23 by the antenna Rx3 and the receiving antenna Rx5 of the first antenna group 22c is the first antenna group spacing Dg1s, which is 4d. The distance between the virtual receiving antennas VR20, VR22, and VR24 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third arrangement direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 4d. The first antenna group interval is Dg1s.

The virtual receiving antenna group 52c has the same configuration as the virtual receiving antenna groups 52a and 52b. In the example of FIG. 44, virtual receiving antennas VR25 to VR36 are arranged toward the positive side in the third arrangement direction dr3, respectively: VR25, VR26, VR31, VR32, VR27, VR28, VR33, VR34, VR29, VR30, VR35, VR36. They are arranged in this order. Of this virtual receiving antenna group 52c, VR25, VR26, VR27, VR28, VR29, and VR30 indicated by solid white circles are virtual reception formed by signals transmitted by the transmitting antenna Tx5 and received by the receiving antennas Rx1 to Rx6. The antennas VR31, VR32, VR33, VR34, VR35, and VR36 indicated by white dashed circles are virtual receiving antennas formed by signals transmitted by the transmitting antenna Tx6 and received by the receiving antennas Rx1 to Rx6.

Virtual reception antennas VR25 and VR26 are virtual reception antennas formed by signals received by reception antennas Rx1 and Rx2 of the first antenna group 22a, and virtual reception antennas VR27 and VR28 are formed by reception antennas Rx3 and Rx4 of the first antenna group 22b. The virtual receiving antennas VR29 and VR30 are virtual receiving antennas formed by the signals received by the receiving antennas Rx5 and Rx6 of the first antenna group 22c. Therefore, the distance between the adjacent virtual receiving antennas VR25, VR27, and VR29 by the receiving antenna Rx1 of the first antenna group 22a, the receiving antenna Rx3 of the first antenna group 22b, and the receiving antenna Rx5 of the first antenna group 22c is 4d. The first antenna group interval is Dg1s. The distance between the virtual receiving antennas VR26, VR28, and VR30 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third arrangement direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 4d. The first antenna group interval is Dg1s.

VR31, VR32, VR33, VR34, VR35, and VR36 shown by the white broken line circles also receive reception from the receiving antenna Rx1 of the first antenna group 22a and the first antenna group 22b, similar to VR25 to VR30 shown by the white solid line circles. The distance between adjacent virtual receiving antennas VR31, VR33, and VR35 by the antenna Rx3 and the receiving antenna Rx5 of the first antenna group 22c is the first antenna group distance Dg1s, which is 4d. The distance between the virtual receiving antennas VR32, VR34, and VR36 formed by the receiving antennas Rx2, Rx4, and Rx6, which are the positive side receiving antennas Rx in the third arrangement direction dr3 in the first antenna sets 22a, 22b, and 22c, is also 4d. The first antenna group interval is Dg1s.

The distance between adjacent first antenna sets 22a, 22b, 22c having two receiving antennas Rx arranged at a distance d, that is, the antenna spacing D1, in the first antenna group Gr1 is One antenna group interval Dg1s is determined according to equation (4). The second antenna group spacing Dg2s between the second antenna groups 24a, 24b, and 24c having two transmitting antennas Tx arranged at the antenna spacing D2, that is, the transmitting antenna spacing Dtx that is twice the distance d in the second antenna group Gr2. , determined according to equation (5).

In the case of the antenna arrangement in FIG. 40, the number β of antennas in the second antenna group is 2, the second antenna At2 of the second antenna group Gr2 is the transmitting antenna Tx, and each antenna of the second antenna group Gr2 is The antenna interval D2 between adjacent second antennas At2 in the two antenna sets 24a, 24b, and 24c is the transmission antenna interval Dtx, which is twice the distance d. In the case of the antenna arrangement shown in FIG. 40, the first antenna group interval Dg1s is 2×D2, which is 4d. Since the first antenna group interval Dg1s is 4d and the first number of antennas Ng1 is 6, the second antenna group interval Dg2s is 12d calculated as 4d×6/2.

As described above, the plurality of first antennas At1 arranged at antenna intervals D1 of a predetermined distance d may be either the transmitting antenna Tx or the receiving antenna Rx. The second antenna At2 is an antenna that operates in the opposite manner to the first antenna At1. In the antenna arrangement of FIG. 40, there are six first antennas At1 and six second antennas At2. However, the antenna in the radar device 1 of the sixth embodiment is not limited to this as described in the fourth and fifth embodiments. It is sufficient that the number of first antennas At1, that is, the number of first antennas Ng1, is an even number of 4 or more, that two or more first antenna groups are provided, and that the number of second antennas At2, that is, the number of second antennas Ng2 is α × β. .

In the radar device 1 of the sixth embodiment, the number of first antennas At1 included in the first antenna group Gr1 is an even number of 4 or more, and the number of second antennas At2 included in the second antenna group Gr2 is α×β. , the transmitting circuit 12 and the receiving circuit 13 correspond to the number of transmitting antennas Tx, which is one of the first antenna At1 and the second antenna At2, and the number of receiving antennas Rx, which is the other of the first antenna At1 and the second antenna At2. It has a corresponding configuration. In the radar device 1 of the sixth embodiment, the first antenna group interval Dg1s, which is the adjacent interval in the first antenna group having two first antennas At1 arranged at a predetermined distance d, is Multiply the number of antennas in the group β, which is the number of second antennas At2 in the two antenna groups 24a, 24b, and 24c, by the antenna spacing D2, which is the spacing between adjacent second antennas At2 in the second antenna groups 24a, 24b, and 24c. The first antenna At1 is arranged so as to have a value of . Further, the radar device 1 of the sixth embodiment has the second antennas At2 of β antennas arranged at an antenna spacing D2, and the adjacent antenna groups 24a, 24b, 24c have α second antenna groups 24a, 24b, 24c. The second antenna At2 is arranged so that the second antenna group interval Dg2s is equal to the product of the first antenna group interval Dg1s and the first number Ng1, which is the number of first antennas At1, divided by 2. ing. In the radar device 1 of the sixth embodiment, although the first antenna At1 of three or more channels cannot be physically arranged at intervals of a predetermined distance d, the transmission and reception of the first antenna At1 and the second antenna At2 Since the plurality of virtual reception antennas VR formed can be arranged at equal intervals of distance d, side lobes can be reduced and false detection can be suppressed.

The radar device 1 of Embodiment 6 is a case where the number β of antennas in the second antenna group of the second antenna group Gr2 in the radar device 1 of Embodiment 5 is 2, and the radar device 1 of Embodiment 5 is It has the same effect as 1.

In the radar device 1 according to the fifth embodiment, which is equipped with antennas having the antenna arrangement shown in FIG. 25 are arranged, and the element antennas 19 are arranged so as not to face each other. In this case, depending on the wavelength λ of the transmission signal transmitted by the radar device 1, the feeding circuit 25 may be located close to the antenna. In this case, the feeding circuit 25 acts as a part of the antenna, and the arrangement pattern of the antenna may be disturbed. An undisturbed antenna arrangement pattern means that the parameters that determine the antenna arrangement pattern, namely the antenna spacing D1, D2, the first antenna group spacing Dg1s, and the second antenna group spacing Dg2s, are within permissible ranges at any location on the antenna. This is the antenna arrangement pattern when it is considered to be a constant value. A disordered antenna arrangement pattern is an antenna arrangement in which the values of the antenna spacing D1, D2, the first antenna group spacing Dg1s, and the second antenna group spacing Dg2s exceed the allowable range depending on the location and are not considered constant values. It's a pattern. If the antenna arrangement pattern is disturbed, the distance, relative velocity, and angle of the target object 33 cannot be accurately measured. However, in the radar device 1 according to the sixth embodiment including the antennas having the antenna arrangement shown in FIG. Since the element antennas 19 are arranged to face each other so that the feeding circuit 25 is not arranged, there is no disturbance in the parameters that determine the arrangement pattern of the antennas, and the distance, relative velocity, and angle of the target object 33 can be accurately determined. can be measured.

When the number of antennas β in the second antenna group of the second antenna group Gr2 is 2, the element antenna 19 is Since the antennas can be arranged to face each other, it is effective as a measure to suppress disturbances in the arrangement pattern of the antennas. Furthermore, even when the width of the feeder circuit 25 is wide, that is, when the width in the second arrangement direction dr2 is wide, the arrangement of the transmitting antenna Tx, which is the second antenna At2 of the second antenna group Gr2 shown in FIG. This is effective for accurately measuring the distance, relative velocity, and angle of the object 33.

Consider the antenna sizes of the first antenna group Gr1 and the second antenna group Gr2. The antenna size of the first antenna group Gr1, that is, the first antenna group size Dg1t, is defined as the length from the most negative phase center line to the most positive phase center line in the first arrangement direction dr1. Similar to the antenna size of the first antenna group Gr1, the antenna size of the second antenna group Gr2, that is, the second antenna group size Dg2t, is from the most negative phase center line to the most positive phase center line in the second arrangement direction dr2. is defined as the length of The radar device 1 of Embodiment 6 equipped with antennas having the antenna arrangement shown in FIG. This is an example in which the number of antennas β is 3 and 2, respectively. For comparison, the first antenna number Ng1 and the second antenna number Ng2 are shown in FIGS. A radar device 1 according to a fourth embodiment including an antenna with an antenna arrangement will also be described. The radar device 1 of the fourth embodiment including the antennas arranged as shown in FIGS. 32 and 33 has a first antenna number Ng1 of 6, a second antenna number Ng2 of 6, and a number α of second antenna groups Gr2. and the number β of antennas in the group are 2 and 3, respectively. As is clear from FIGS. 32, 33, and 40, the first antenna group size Dg1t is expressed by equation (6), and the second antenna group size Dg2t is expressed by equation (7).

Dg1t=Dg1s×(Ng1/2-1)+D1
=D2×β×(Ng1/2-1)+D1...(6)
Dg2t=Dg2s×(α-1)+D2×(β-1)
=Dg1s×Ng1/2×(α-1)+D2×(β-1)
=β×D2×Ng1/2×(α-1)+D2×(β-1)
...(7)
Note that in FIGS. 32, 33, and 40, the antenna spacings D1 and D2 are d and 2d, respectively.

In the radar device 1 according to the sixth embodiment, which is equipped with antennas having the antenna arrangement shown in FIG. From equation (7), the first antenna group size Dg1t and the second antenna group size Dg2t are 9d and 26d, respectively. In the radar device 1 according to the fourth embodiment including the antennas having the antenna arrangements shown in FIGS. 32 and 33, the number α of the second antenna group Gr2 and the number β of antennas in the group are 2 and 3, respectively, and the formula ( 6), from equation (7), the first antenna group size Dg1t and the second antenna group size Dg2t are 13d and 22d, respectively. In either case, the second antenna group size Dg2t is larger than the first antenna group size Dg1t, so when reducing the longitudinal width of the radar device 1, that is, the width in the second arrangement direction dr2, the second antenna group size Dg2t is larger than the first antenna group size Dg1t. It is better to select 2 as the number of sets α of Gr2. Therefore, if there is no disturbance in the parameters determining the antenna arrangement pattern, the longitudinal width of the radar device 1 can be reduced by selecting the number α of the second antenna group Gr2 to be 2. On the other hand, if the number α of the second antenna group Gr2 is selected to 2, and the wavelength λ used causes a disturbance in the parameters that determine the antenna arrangement pattern, the number α of the second antenna group Gr2 can be set to 2. By selecting 3, the distance, relative velocity, and angle of the target object 33 can be accurately measured.

Depending on the position where the radar device 1 is mounted, there may be restrictions on the width in the longitudinal direction, which is the longer width of the radar device 1. For example, when the radar device 1 is mounted near a bumper of a vehicle, it may be required to reduce the width in the longitudinal direction due to constraints on surrounding structures and the shape of the bumper. When considering a design that reduces the width of the radar device 1 in the longitudinal direction, a configuration in which the transmitting antenna Tx and the receiving antenna Rx are arranged in the vertical direction, that is, in the direction in which the phase center line extends, can be considered. In this case, the longitudinal width of the radar device 1 is larger than either the longitudinal width of the entire transmitting antenna Tx or the longitudinal width of the entire receiving antenna Rx. A radar device 1 is required in which the width in the direction or the width in the longitudinal direction of the entire receiving antenna Rx is as small as possible. In such a case, the number α of the second antenna group Gr2 may be selected to be two.

It should be noted that although this application describes various exemplary embodiments and examples, various features, aspects, and functions described in one or more embodiments may not be applicable to specific embodiments. The present invention is not limited to application, but can be applied to the embodiments alone or in various combinations. Accordingly, countless variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, the present invention includes cases in which at least one component is modified, added, or omitted, and cases in which at least one component is extracted and combined with components in other embodiments.

DESCRIPTION OF SYMBOLS 1... Radar device, 11... Processing part, 19... Element antenna, 22a, 22b, 22c... First antenna group, 24a, 24b, 24c... Second antenna group, 25, 25a, 25b, 25c, 25d, 25e, 25f ...Feeding circuit, 33...Target object, 50...Virtual receiving antenna group, 51a, 51b, 51c...Virtual receiving antenna group, 52a, 52b, 52c...Virtual receiving antenna group, At1, At1a, At1b...First antenna, At2, At2a, At2b, At2c, At2d...second antenna, d...distance (basic distance), D1...antenna spacing, D2...antenna spacing (second antenna spacing), dr1...first array direction, dr2...second array direction, dr3...Third arrangement direction, dr4...Fourth arrangement direction, dr5...Fifth arrangement direction, Dg1s...First antenna group spacing, Dg2s...Second antenna group spacing, Dvr...Virtual reception antenna spacing, Gr1...First antenna group , Gr2...Second antenna group, Ng1...Number of first antennas, Ng2...Number of second antennas, Rx, Rx1, Rx2, Rx3, Rx4, Rx5, Rx6...Receiving antenna, Tx, Tx1, Tx2, Tx3, Tx4, Tx5 , Tx6, Tx7, Tx8, Tx9...Transmitting antenna, VR...Virtual receiving antenna, VR1, VR2, VR3, VR4, VR5, VR6, VR7, VR8, VR9, VR10...Virtual receiving antenna, VR11, VR12, VR13, VR14, VR15, VR16, VR17, VR18, VR19, VR20...Virtual receiving antenna, VR21, VR22, VR23, VR24, VR25, VR26, VR27, VR28, VR29, VR30...Virtual receiving antenna, VR31, VR32, VR33, VR34, VR35, VR36, VR37, VR38, VR39, VR40...virtual receiving antenna, VR41, VR42, VR43, VR44, VR45, VR46, VR47, VR48, VR49, VR50...virtual receiving antenna, VR51, VR52, VR53, VR54...virtual receiving antenna, α... Number of groups (number of second antenna groups), β... Number of antennas in a group (number of antennas in second antenna group)

Claims (14)

A plurality of transmitting antennas that radiate a transmitted signal toward a target object, a plurality of receiving antennas that receive a reflected signal obtained by reflecting the transmitted signal from the target object, and output it as a received signal, and a plurality of the receiving antennas. a processing unit that processes the received signals output from each of the radar apparatuses,
The basic distance is the antenna spacing between adjacent antennas, which is determined based on the field of view required for the radar device,
The antenna group includes either a plurality of the transmitting antennas or a plurality of the receiving antennas, and the antenna group includes a first antenna group having a plurality of first antennas in which an antenna spacing between adjacent antennas is the basic distance. Let the antenna group be the first antenna group,
The antenna group includes a plurality of other antennas different from the first antenna of the first antenna group, and the antenna group includes a plurality of second antennas in which an antenna spacing between adjacent antennas is twice the basic distance. The antenna group having two antenna sets is referred to as a second antenna group,
The first antenna and the second antenna include a plurality of element antennas and a power feeding circuit that feeds power to the element antennas,
The plurality of first antennas are arranged side by side in a first arrangement direction perpendicular to the transmission direction of the transmission signal, and each of the first antennas has the feeding circuit on a positive side or a negative side of the first arrangement direction. ,
The plurality of second antennas are arranged in a second arrangement direction perpendicular to the transmission direction of the transmission signal and parallel to the first arrangement direction, and the feeding circuit is arranged on the positive side or negative side of the second arrangement direction. Has it on the side,
No feeding circuit is disposed between adjacent antennas in the first antenna group,
A virtual reception antenna group composed of a plurality of virtual reception antennas formed by the plurality of first antennas of the first antenna group and the plurality of second antennas of the second antenna group is arranged in a direction in which the transmission signal is transmitted. are arranged side by side in a third arrangement direction perpendicular to and parallel to the first arrangement direction and the second arrangement direction, and the interval between adjacent virtual receiving antennas in the third arrangement direction is the basic distance.
radar equipment. A plurality of transmitting antennas that radiate a transmitted signal toward a target object, a plurality of receiving antennas that receive a reflected signal obtained by reflecting the transmitted signal from the target object, and output it as a received signal, and a plurality of the receiving antennas. a processing unit that processes the received signals output from each of the radar apparatuses,
The basic distance is the antenna spacing between adjacent antennas, which is determined based on the field of view required for the radar device,
The antenna group includes either a plurality of the transmitting antennas or a plurality of the receiving antennas, and the antenna group includes a first antenna group having a plurality of first antennas in which an antenna spacing between adjacent antennas is the basic distance. Let the antenna group be the first antenna group,
The antenna group includes a plurality of other antennas different from the first antenna of the first antenna group, and the antenna group includes a plurality of second antennas in which an antenna spacing between adjacent antennas is twice the basic distance. The antenna group having two antenna sets is referred to as a second antenna group,
The plurality of first antennas are antennas arranged in a first arrangement direction perpendicular to the transmission direction of the transmission signal and have a fractional band of 2% or more and 10% or less,
The plurality of second antennas are antennas that are arranged in a second arrangement direction perpendicular to the transmission direction of the transmission signal and parallel to the first arrangement direction, and have a fractional band of 2% or more and 10% or less,
A feeding circuit for supplying power to the first antenna is not arranged between adjacent antennas in the first antenna group,
A virtual reception antenna group composed of a plurality of virtual reception antennas formed by the plurality of first antennas of the first antenna group and the plurality of second antennas of the second antenna group is arranged in a direction in which the transmission signal is transmitted. are arranged side by side in a third arrangement direction perpendicular to and parallel to the first arrangement direction and the second arrangement direction, and the interval between adjacent virtual receiving antennas in the third arrangement direction is the basic distance.
radar equipment. The radar device according to claim 1 or 2, wherein the first antenna is the transmitting antenna and the second antenna is the receiving antenna. The radar device according to claim 1 or 2, wherein the first antenna is the receiving antenna and the second antenna is the transmitting antenna. The first antenna group has two first antennas and one first antenna group,
The radar device according to any one of claims 1 to 4. The first antenna group includes two or more first antenna groups,
The second antenna group has a second antenna number of 2 or more, which is the number of the second antennas,
An antenna interval between the adjacent second antennas that is twice the basic distance is a second antenna interval,
The first antenna group spacing, which is the spacing between the adjacent first antenna groups, is a value obtained by multiplying the number of second antennas and the second antenna spacing.
The radar device according to any one of claims 1 to 4. In the second antenna group, the number of second antennas is a prime number of 2 or more,
The radar device according to claim 6. The first antenna group has two or more first antenna groups, and the number of first antennas, which is the number of first antennas, is an even number of four or more,
An antenna interval between the adjacent second antennas that is twice the basic distance is a second antenna interval,
The number of the second antenna groups is the number of second antenna groups, and the number of antennas in the second antenna group is the number of antennas in the second antenna group,
In the second antenna group, the number of second antennas, which is the number of the second antennas, is a value obtained by multiplying the number of second antenna groups and the number of antennas in the second antenna group,
The first antenna group spacing, which is the spacing between the adjacent first antenna groups, is a value obtained by multiplying the number of antennas in the second antenna group by the second antenna spacing,
The second antenna group spacing, which is the spacing between the adjacent second antenna groups, is a value obtained by dividing the product of the first antenna group spacing and the first number of antennas by 2.
The radar device according to any one of claims 1 to 4. The radar device according to claim 8, wherein the number of second antenna sets is two. The number of antennas in the second antenna group is two, and no feeding circuit is disposed between adjacent antennas in the second antenna group.
The radar device according to claim 8. The radar device according to any one of claims 1 to 10, wherein the first antenna group includes the first antennas arranged offset in a direction perpendicular to the first arrangement direction. The radar device according to any one of claims 1 to 11, wherein the second antenna group includes the second antennas arranged shifted in a direction perpendicular to the second arrangement direction. The first antenna group has the same configuration as the A group and a plurality of first antennas arranged in the first arrangement direction, and the first antenna group has the same configuration as the A group, and has a plurality of first antennas arranged in the first arrangement direction. A group B is arranged.
The radar device according to any one of claims 1 to 12. The second antenna group has a C group having a plurality of second antennas arranged in the second arrangement direction, and has the same configuration as the C group, and is arranged in a direction perpendicular to the second arrangement direction. and a D group arranged.
The radar device according to any one of claims 1 to 13.

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